Band Saw Log Mill with Reciprocating Cradle for Core Alignment

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional sawmills using circular saws result in excessive loss of the valuable center core of logs due to wide kerf and difficulty in accurately cutting through the center core, especially in non-symmetrical logs, leading to suboptimal yield of high-quality boards.

Innovation Solution

A sawmill equipped with a band saw and a log positioning rig featuring a reciprocating cradle and actuator to align the central core of the log with the band saw blade, along with log lifting arms and dogs for secure positioning, allowing precise cutting through the log's core with a thinner kerf.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If a circular saw is used to halve a log, then the cutting operation can be performed, but the wide kerf results in excessive loss of the valuable center core of the log

Engineering Contradiction:

Improveloss of center coreVSAvoidcutting operation

Core Design Contradiction:

Loss of substanceVSEase of manufacture

Solution Approach 1:

The patent changes the fundamental parameter of kerf width by replacing the circular saw with a band saw. The band saw blade is significantly thinner than a circular saw blade, thereby reducing the material removed during cutting and minimizing loss of the valuable center core while still achieving effective log halving

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the log is positioned for circular saw cutting, then the saw can cut through the log, but the log is not always symmetrical resulting in inaccurate cutting through the center core

Engineering Contradiction:

Improvealignment of center core with saw bladeVSAvoidlog positioning

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent replaces manual log positioning with an automated laser alignment system. The laser projects a reference line that guides the positioning of the log, ensuring accurate alignment of the center core with the band saw blade without relying on operator skill or manual measurement

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The laser alignment system acts as an intermediary between the operator and the log positioning task. It provides visual feedback through projected lines that indicate correct positioning, serving as a mediator that translates complex alignment requirements into simple visual cues

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of substance

If a band saw is used instead of a circular saw, then the kerf is reduced, but additional positioning mechanisms are required

Engineering Contradiction:

Improvekerf widthVSAvoidpositioning rig

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The positioning rig employs dynamic, adjustable components including movable cradles and adjustable support rollers that can be positioned along the log length. This dynamic design allows the system to adapt to logs of varying sizes and shapes while maintaining simplicity, rather than requiring fixed, complex mechanisms for each possible log configuration

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution enables more efficient and accurate cutting through the log's core, increasing the yield of usable boards, reducing operational costs, and requiring less horsepower compared to conventional circular sawmills, while being easier to set up and maintain.

Implementation Method 1

The reciprocating cradle is pivotally attached to the fixed frame, and is configured for raising or lowering the first end of the log to align the central core of the log along the length of the log with a blade of the band saw

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 2

an actuator attached to a first end of the reciprocating cradle and to the fixed frame, wherein the actuator is configured for raising or lowering the first end of the reciprocating cradle to center the central core of the log with the blade of the band saw

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

a laser attached to the fixed frame, wherein the laser is configured for aligning the central core of the log with the blade of the saw

Methodology Applied

Scientific EffectLaser: Laser

Implementation Method 4

The band saw is disposed on a movable carriage of a fixed frame, the band saw being configured for sawing a log from a first end of the log to a distal end of the log

Methodology Applied

Scientific EffectAbrasion: Abrasion

Data Source

PatentUS11780110B1Sawmill

Publication Date: 2023.10.10 COLLIER CHARLES R

AI summary

A sawmill for sawing a log segment in two through the core thereof and a method of sawing a log in half through the core thereof. The sawmill includes a log feed conveyor configured for feeding logs to a band saw and a log positioning rig, the band saw being disposed on a movable carriage of a fixed frame, the band saw being configured for sawing a log from a first end of the log to a distal end of the log. The log positioning rig has a reciprocating cradle having a plurality of spaced-apart cradle segments. The reciprocating cradle is pivotally attached to the fixed frame, and is configured for raising or lowering the first end of the log to align the central core of the log along the length of the log with a blade of the band saw.