Patent Application
20220388195
The invention relates to a hold-down shoe assembly that is adjustable to adjust all of the hold-down shoes up and down as a unit, a planermill trimmer having the assembly mounted thereon, and a method of using the hold-down shoe assembly to hold down lumber during end cutting by a planer mill trimmer.
In a sawmilling operation, multi-saw trimmers with saws on nominal 2 foot centers are used to trim both the near end (NE) and far end (FE) of each piece of lumber. The boards are conveyed laterally through the trimmer on lugs at a high rate of speed and each saw raises (and lowers) at the appropriate time to trim the end of the piece according to a manual input, optimized solution (green systems) or grader solution (planermill systems).
Each saw must have a “hold-down” of some sort beside it to 1) hold down the board while sawing, 2) cause the cut-off end to drop out to the waste conveyor below, 3) allow the board to exit the trimmer straight without skewing crossways and 4) keep the board from kicking out of the infeed (or outfeed) of the trimmer, causing damage to equipment or physical injury to surrounding personnel.
In a green system, the boards can be varying thicknesses from 1 inch (or less) up to 6 inch (or more). In this case, the hold-down shoe must be designed to allow each piece the enter under the shoe and into the hold-down (sawing) area. This is not optimal (for speed), but is designed to be the best it can be considering the thickness that must be run through the trimmer. One disadvantage is that the angle of the shoe is different (and not flat at the sawing area) based on the thickness of lumber being sawn.
In a dry (or planermill) system, only one thickness piece is run through the trimmer at a time. This thickness (based on nominal size entering planermill and planer thickness setting) is usually run for several days at a time. This allows for a hold-down shoe that can be optimally set for the incoming lumber thickness. Planermill lumber board piece counts are much higher than sawmill (green) lumber board piece counts.
In years past, some planermill trimmers have been made with adjustable mechanisms with straps attached to the rear of the shoe, as shown in
The present invention solves the problems of thick lumber slamming off of the conventional hold-down shoes. The present invention also provides a far simpler and efficient method of adjusting all of the hold-down shoes simultaneously, and without changing the angle of the hold-down shoes for each thickness of lumber being trimmed.
The objectives of the invention and other objectives can be obtained by an adjustable hold-down shoe assembly comprising:
The objectives of the invention and other objectives can also be obtained by a planermill trimmer comprising:
The objectives of the invention can be further obtained by a method of cutting lumber in a planer mill comprising:
The invention will now be explained with reference to the attached non-limiting drawings. To facilitate an understanding of the principles and features of the various embodiments of the present invention, various illustrative embodiments are explained below. Although example embodiments of the present invention are explained in detail, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the present invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or examples. The present invention is capable of other embodiments and of being practiced or carried out in various ways.
As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include composition of a plurality of components. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named.
Also, in describing the example embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.
It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a composition does not preclude the presence of additional components than those expressly identified. Such other components or steps not described herein can include, but are not limited to, for example, similar components or steps that are developed after development of the disclosed technology.
While certain implementations of the disclosed technology have been described in connection with what is presently considered to be the most practical and various implementations, it is to be understood that the disclosed technology is not to be limited to the disclosed implementations, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
In an example of the present invention produced, the hold-down shoes 6 were mounted on the assembly body 30 with about 2 feet between centers of the hold-down shoes 6. Any desired distance between the hold-down shoes 6 can be utilized. The assembly body 30 comprised a tube that spanned across the front of the planer trimmer 2 and allowed the lumber 12 to pass beneath the assembly body 30. Each of the hold-down shoes 6 has an associated airbag 8. The air-bag 8 can be adjusted to add additional hold-down pressure (bias) on the lumber 12 being end trimmed. Air-bags 8 are now well known and any suitable air-bag 8 and associated equipment to operate and control the air-bag 8 can be utilized.
Since the entire assembly body 30 with all of the hold-down shoes 6 can be adjusted up and down in relation to the conveyor 10, the angle 36 for each different size of lumber can remain the same and the hold-down shoes 6 do not hammer off the back of the lumber 12 when the angled lumber surface 16 contacts the lumber 12. Furthermore, each piece of lumber 12 can now come gently into the angled lumber surface 16 without fear of rolling larger lumber 12, such as square 4 inch×4 inch or 6 inch×6 inch lumber 12.
In order to add strength in a y-axis (vertical) for the full-spanning tube (assembly body 30) with the hold-down shoes 6 attached, several racks (gear 22 and plate 24) can be attached across the span of the assembly body 30.
The lifting/lowering motor 28 can be a servo motor (with encoder feedback) for setworks placement. If desired, the lifting/lowering motor 28 can be replaced with a hand-crank for manual adjustment. Another example of the lifting/lowering device includes an electric or hydraulic cylinder, with or without electronic feedback. In the present example, the lifting/lowering motor 28 was an electric motor with absolute encoder (for position feedback) and electric brake for holding position during operation. In this manner, the settings can be the same for a number of shifts or days. A self-locking reducer can be utilized. However, a brake is preferably used to ensure that the assembly body 30 does not move during operation of the planermill trimmer 2. The settings of the servo motor hold-down shoes can be done by a computer system 40 based on the product thickness being manufactured.
In the current design, the mechanism will mount directly to the front of the Timber Automation trimmer, but it is envisioned that future designs for trimmers manufactured by other OEMS, the mechanism could be made free-standing as well.
It is to be understood that the foregoing illustrative embodiments have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the invention. Words used herein are words of description and illustration, rather than words of limitation. In addition, the advantages and objectives described herein may not be realized by each and every embodiment practicing the present invention. Further, although the invention has been described herein with reference to particular structure, steps and/or embodiments, the invention is not intended to be limited to the particulars disclosed herein. Rather, the invention extends to all functionally equivalent structures, processes and uses, such as are within the scope of the appended claims. Those skilled in the art, having the benefit of the teachings of this specification, may affect numerous modifications thereto and changes may be made without departing from the scope and spirit of the invention.
| Number | Date | Country | |
|---|---|---|---|
| 63197543 | Jun 2021 | US |
