Patent Application
20210162623
This disclosure relates generally to an apparatus and method for heating treating wood.
The following paragraphs are not an admission that anything discussed in them is prior art or part of the knowledge of persons skilled in the art.
A traditional Japanese process for treating wood comprises intensely burning and brushing the wood as a preservative heat treatment. It may be known as Shou Sugi Ban or Yakisugi. It is commonly applied to cypress. The heat treatment is alleged to improve siding longevity by preventing decay and insect infestation, to make wood planks more dimensionally stable, and to improve fire retardancy.
Such treatment many also create grain patterns in the wood, that are considered attractive. The process may only require heat treatment and brushing, so there are no potential allergens added, which may be desirable for some commercial and office applications.
Traditionally, the Shou Sugi Ban process was done over an open fire, banding three boards together into a triangular chimney, and standing it over the fire. The fire would burn up the inside of the boards, then be knocked apart. Then any fire on the boards would be extinguished and the boards brushed. More recent techniques have been developed, but these are largely unsuitable for production quantities,
The following paragraphs are intended to introduce the reader to the more detailed description that follows and not to define or limit the claimed subject matter. This summary is intended to introduce the reader to the more detailed description that follows and not to limit or define any claimed or as yet unclaimed invention. One or more inventions may reside in any combination or sub-combination of the elements or process steps disclosed in any part of this document including its claims and figures.
For better understanding of the present invention and to show more clearly how it may be carried out in effect, reference will now be made, by way of example, to the drawings which show an example of an apparatus of the present disclosure and in which:
Various apparatuses or methods will be described below to provide an example of an embodiment of each claimed invention. No embodiment described below limits any claimed invention and any claimed invention may cover apparatuses and methods that differ from those described below. The claimed inventions are not limited to apparatuses and methods having all of the features of any one apparatus or method described below, or to features common to multiple or all of the apparatuses or methods described below. It is possible that an apparatus or method described below is not an embodiment of any claimed invention. Any invention disclosed in an apparatus or method described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicant(s), inventor(s) and/or owner(s) do not intend to abandon, disclaim or dedicate to the public any such invention by its disclosure in this document.
For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements or steps. In addition, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments generally described herein. Furthermore, this description is not to be considered as limiting the scope of the embodiments described herein in any way, but rather as merely describing the implementation of various embodiments as described.
The apparatus of the present disclosure has a main frame 10, which has longitudinal frame members 12. Supporting legs 14 support the longitudinal frame members 12, and diagonal bracing members 16 connect to the supporting legs 14 to the frame members 12. The longitudinal frame members 12 may be I section members, and both the supporting legs 14 and bracing members 16 may be square section channels, welded to the longitudinal frame members 12.
Cross or tie members 18 extending between and beneath the longitudinal frame members 12. The tie members 18 may also be square section channels, welded to the frame members 12. Optionally, to enable ready movement of the apparatus, wheels 20, which include, but are not limited to, caster wheels, are mounted on the supporting legs 14.
Upper L section channel members 30 are mounted on the longitudinal frame members 12, with horizontal flanges 36 extending inwardly towards one another. Lower L channel members 32 are secured, e.g. by welding, to the supporting legs 14, below the longitudinal frame members 12. Additionally, vertical support members 38 may be provided to support these lower L channel members 32. As for the upper channel members 30, the lower channel members 32 have horizontal flanges 36 extending inwardly and towards one another. At a discharge end, as shown in
A steel chain conveyor belt 50 is provided for supporting and transporting wood boards 95. The conveyor belt 50 may be formed from any suitable material and in any suitable manner that is capable of supporting the wood boards or planks 95. The conveyor belt provides a generally planar surface that supports and conveys the wood boards or planks 95. It may not require any elements to engage the wood boards or planks 95. Where a particularly vigorous brushing action is provided, the belt 50 may include projecting elements to engage wood boards or planks 95 to prevent them slipping on the conveyor 50. It will be understood that, in use, the conveyor generally not be completely covered by wood boards or planks 95, so that parts of the conveyor will be subject to the full radiant heat from a burner assembly 90 detailed below. Thus, the conveyor 50 will be formed from steel or other material capable of withstanding the heat from the burner assembly 90.
Along the length of the apparatus, the L channel members 30 serve to support the steel chain conveyor belt 50 in a first direction, and the L channel members 32 serve to support the steel chain conveyor belt 50 in a second, return direction. At a discharge end of the apparatus, there is a drive shaft 52 on, mounted in a pair of bearings, which in turn are mounted on the ends of the longitudinal frame members 12. On the drive shaft 52, between the bearings 54, there are 3 toothed sprocket wheels 56 (not shown in detail), with two sprocket wheels mounted to engage outer edges of the conveyor belt 50, and a third sprocket mounted to engage the centre line of the conveyor belt 50. The drive shaft 52 and sprocket wheels may be in the form of a cylinder with teeth providing the sprocket drive.
As shown in
On the other end of the drive shaft 52, on the discharge end of the apparatus, there is mounted a drive sprocket 62, for driving brushes, as shown in
As shown in
Above the longitudinal frame members 12, there are a number of additional frame elements. Two inverted U frames 70 and 72 have side legs, which may be square section channels, welded or otherwise secured to the longitudinal frame members 12. The U frames 70 and 72 have top members, which may be inverted U section channels, connected to the side legs and providing respective threaded mounts 74 and 76 for respective screw mounting shafts 78 and 80.
As best shown in
The screw shafts 78, 80, at their lower ends are mounted for rotation in flanges secured to the longitudinal tube 92. For example and as shown, knots can be secured to the shafts 78, 80 both above and below each of the flanges, so that the screw shafts simply rotate within apertures in the flanges. As shown, handles, 82, 84 are provided at the upper end of the screw shafts 78, 80, for rotating the shafts stop rotation of the shaft 78, 80, in their screw mounts 74, 76 can be used to raise and lower the infrared radiant heater or burner assembly 90 as required.
To provide additional guidance or alignment to the radiant heater or burner assembly 90, brackets 102 can be provided.
To further inverted frames 110, 112, which are generally similar, are also mounted to the longitudinal frame members 12. Each inverted frame 110, 112 comprises an inverted U-shape channel 114, and a pair of legs 116 on one side and a pair of legs 118 on the other side. As shown in
First and second cylindrical brushes 120, 122 are mounted on the shaft, with the shafts mounted in pairs of respective bearings 124,126. On one side, for each of the cylindrical brushes 120, 122, a mounting shaft 142, 144, extends through the respective bearing 124, 126, for mounting of a respective drive sprocket 128, 130. An idler sprocket 132 is mounted to a support bracket 134. A further idler and tension sprocket 136 is rotatably mounted on the end of an arm 138 that is pivotally mounted to a flange attached to one of the bracing members 16. The tension spring 140 is connected between the arm 138 and the bracing member 16.
A drive chain 150 engages all of the sprockets 62, 128, 130, 132 and 136. The tension and idler sprocket 136 ensures that the chain is maintained in tension. The idler sprocket 132 ensures that the chain 150 fully engages both of the drive sprockets 128, 130. As detailed below, the bearings 124 and 126 are mounted for vertical sliding movement in the side legs 116, 118, to permit vertical adjustment of the position of the cylindrical brushes 120, 122. The provision of the idler and tension sprocket 136, and its range of motion ensures that a suitable tension can be maintained in the chain 150, irrespective of the vertical position of the brushes 120, 122.
As explained below, to accommodate different thicknesses of boards, and to enable the intensity of the brushing to be varied, the vertical position of the brushes 120, 122 is adjustable. To this end, the bearings 124, 126 are slidably mounted in the side legs 116, 118. In a similar manner to the adjustment for the radiant heater or burner assembly 90, pairs of respective threaded shafts are provided for the brushes 120, 122. Each threaded shaft 142, 144, at its lower end, may have a pair of nuts secure thereto, and on either side of the flanges of the bearings 124, 126, so as to provide a simple, rotating support for the respective brush 120, 122. At its upper end, each mounting shaft 142, 144 may be provided with further nuts, as shown, on either side of the inverted U-shaped channel 114. By adjusting the position of these nuts along the shafts 142, 144, the vertical position of the shafts 142, 144, and hence the vertical location of the brushes 120, 122 can be adjusted.
A further and final inverted frame 160 is attached to the longitudinal frame members 12. A damping cloth 161 is mounted to this frame 160. For this purpose, the cloth 161 could be formed to provide an elongate channel into which a rod 162 is inserted. In known manner, the rod 162 can be supported, at either end, in brackets 164 and secured with clips 166.
The frame 160 is also provided with spray nozzles 168 that would be connected to a water source.
In use, the electric drive motor 58 is used to drive the sprockets 56, to pull the chain conveyor belt along a top run in the upper channel members 30, from the end shaft 65 towards the damping cloth 162. The chain conveyor belt, returns, in a lower run supported by the lower channel members 32, below the top run. As shown, the length of the chain is such as to leave a substantial loop of the chain conveyor belt hanging between the ends of the lower channel members 32 and the end shaft 65. This loop is dimensioned to have sufficient weight, to provide sufficient attention to pull the chain conveyor belt 50 along the channel members 32 and to maintain that lower run of the conveyor belt generally in tension, as shown.
Simultaneously, as the motor drives the conveyor belt 50, the drive sprocket 62, on the end of the drive shaft 52, drives the chain 150. Consequently, the chain 150 drives the cylindrical brushes 120, 122 causing the brushes to rotate clockwise, as viewed in
It will therefore be understood that this basic configuration provides for the chain conveyor belt to transport wood boards or planks 95 from one end, under the infrared radiant heater or burner assembly 90, under the brushes 120, 122 and under the damping cloth 162, to be discharged from the apparatus.
To achieve a desired charring and heat treatment of the wood boards or planks 95, a number of parameters can be varied. Firstly, the speed of the chain conveyor belt 50 can be varied as desired. In this configuration, this will inherently vary the rotational speed of the rotating brushes 120, 122. It will be understood that, in alternate configurations, a separate drive can be provided to the brushes 120, 122, so that their speed can be independent of the speed of the chain conveyor belt 50.
A number of parameters of the infrared radiant heater or burner assembly 90 can be varied. Firstly, using the mounting shafts 78, 80, the height of the radiant heater or burner assembly 90 can be adjusted as desired. The height can be adjusted, for example, in accordance with the thickness of the wood boards or planks 95 being treated and/or in accordance with the desired height or spacing between the radiant heaters or burners 94 and the wood boards or planks 95, which in turn may depend upon the type of wood 95 being treated.
The level of radiant heat provided by the radiant heater or burner assembly 90 can also be adjusted. Thus, the number of radiant heaters or burners 94 that are actually activated for anyone treatment session can be adjusted, and it is not necessary for all of the banners to be lit. In addition, the heat provided by each radiant heater or burner 94 can be adjusted, by adjusting the amount of gas supplied to it.
The height of the brushes 120, 122 can be adjusted. As for the radiant heater or burner assembly 90, the thickness of the wood boards or planks 95 being treated may be a parameter used to determine the height of the brushes. Additionally, the height of the brushes 120, and 22 may be varied depending upon, for example, the level of brushing required, the hardness or other qualities of the wood 95 being treated.
Examples of variations in parameters for different elements of the apparatus for different types of wood are given in the following table:
As indicated in the above table, the various parameters can be adjusted for different types of wood 95. The conveyor speed is expressed in feet per minute (fpm). The heights for the burner assembly 90 and the brushes 120, 122 are expressed in inches above the level of the conveyor 50. For the burner assembly 90, this measurement is the distance between the bottom of the individual burners 94 and the top of the conveyor 50. For the brushes, the measurement again is in inches and is measured between the lowermost point of the brushes 120, 122 when not in contact with the wood and the conveyor 50. It will be understood that, to achieve the necessary brushing action, the lowermost point of the brushes needs to be below the top of the wood board.
For this purpose allowance has to be made for the fact that the actual thickness of wood boards or planks 95 (at least in N. America) is less than a nominal dimension or thickness of the lumber, before it's dressed/planed. For example, for a ¾″ thick cedar board, the actual thickness may only be about ⅝″ thick. Accordingly, the brushes 122, 124 may be set at ½″ above the conveyor 50, which will put the extended bristles of the brush at ⅛″ below the surface of the board. The bristles will bend when they come in contact with the board, which will provide the necessary pressure and brushing action.
The heat treatment of the wood boards or planks 95 is intended to affect significant charring of the wood 95, to provide an attractive appearance and/or to enhance the appearance of the wood 95. In many cases, the level of heat will be such that the wood 95 catches fire, to some extent, as shown in
While the apparatus and method have been described as including rotating brushes. The present disclosure envisages that any suitable motion can be applied to the brushes that will effect the required brushing action. For example, the brushes can have a planar brushing surface and be provided with oscillating movements along a line, which be aligned with the direction of motion of the wood board or at an angle to the wood board. It is also possible that a brush or brushes can be mounted for rotation about an axis perpendicular to the surface of the wood board, the rotation being either continuous or oscillating.
A number of embodiments have been described herein. However, it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the embodiments as defined in the claims appended hereto. A person skilled in the art will also recognize that the embodiments described above should be read as representative of a plethora of permutations and combinations not explicitly described, the permutations and combinations incorporating elements from various embodiments. More particularly, other variants may comprise any possible, practical combinations of features disclosed in the claims, beyond those defined by the claims and their dependencies.
This application claims the benefit of Provisional Application Ser. No. 62/942,845, filed Dec. 3, 2019, which is hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62942845 | Dec 2019 | US |
