Machines

Hedlund's machines cover a wide range of process solutions for log handling, from loading of logs up to the sawing process. Here is a brief insight and overview into our machine range. Contact us if you want to know more and we will help you find the best solution for your specific needs!

Log screw feeder

The modern, versatile and flexible machine that fulfils many purposes. Receives and aligns logs. Even-ends and conveys logs one by one. Installed angled it elevates logs in height. Breaks up log bundles after a log deck. Quiet and soft operation. Simple and robust construction. Frequency controlled electric motor drive. Fits in many places in sawmill infeeds and log sorting and can often replace older technology with a better function.

 

Furthermore, length, width and angle can be easily configured to fit into existing installations for the desired diameter range of logs.

Log turners

Hedlund’s log turner family consists of three different machines with unique properties that together cover a variety of different types of process solutions with varying capacities.

Revolver turner

The Revolver turner is our most compact turner solution. The direct-driven, turner spider turns incoming logs 90° around its centre. When leaving the incoming log conveyor, the log is transported on gear motor powered rollers, preventing slippage and resulting in more accurate turning and a more consistent result. Furthermore, the log leaves the incoming log conveyor before turned which will reduce wear and noise on that conveyor.

After turning, the log falls into either a bottom conveyor for further transport in the axial direction or a ‘bottom discharge’ which indexes the log in the radial direction allowing a slightly higher capacity. Both solutions are suspended in rubber elements and the conveyor frames are, where technically possible, sand-filled to reduce both noise emission and vibrations. The turner spider can also be retrofit to existing hydraulic turners. Watch the movie here!

 

Turntable

The turntable turns the logs 180° in an axial direction via a large diameter driven plate in a continuous flow. Continuous operation allows high capacity and reliability with low noise.

 

Curve turner

A curve turner is the uncompromising alternative when it comes to high piece count combined with quiet operation. Curve turners come in two different configurations, 180° or 90° + 90°, both having the same function but with flexibility in the design of the entire system layout. In the case of curve turning, the log flow is divided in two separate sub-flows where logs to be turned go “off-line” and are transversely fed 180° on a continuous curve chain conveyor to be merged with the main flow. Alternatively, both flows go 90° and merge. Since the total capacity can be seen as the sum of the two sub-flows, the theoretical piece count reaches 60 logs per minute.

Log sorting conveyors

Log sorting takes place on a longitudinal conveyor with kickers to log bins on both sides of the conveyor. The conveyor is modular where drive- and turn ends together with the desired number of sorting modules are combined. Log discharge is made by underlying, frequency controlled electric kickers, which quickly and accurately kick the log in exactly the right moment and then return to their initial position. Precision is extremely important as logs can be transported in up to 180 m/min. with short gaps and must be placed in exact position to maintain good order in the log bins. With our control system along with an elaborated bin and guide rail design, accuracy is guaranteed. Compared to hydraulic systems, the electric system is more accurate, it is winter proof, easier to maintain and gives no environmental problems.

Log conveyors

Hedlund’s log conveyors come in a variety of versions and designs for all applications. In its basic design, our log conveyors are manufactured in ‘high speed design’, i.e. with large sprockets where the chain enters tangentially for reduced chain clatter and quieter operation at speeds up to 200 m/min. Conveyor chains are delivered in heavy duty design with welded carriers in Hardox® material for increased wear properties. Split design nylon sprockets for low noise and long service life, fitted with Timken® steel bearing housings and powered exclusively via shaft mounted electric gear motors.

 

There are a variety of options for our log conveyors, such as semi-automatic hydraulic tensioning, various noise reduction measures and different types of sliding surfaces. Below are more purpose-specific configurations of the log conveyors. Please note that our log sorting conveyor and kicker versions are described under their own heading.

 

Reception conveyors

Our reception conveyor with open infeed side for receiving transversely fed logs is designed with a reinforced frame and high side plate side for increased service life under harsh operating conditions. The entire machine is mounted on a rubber suspension which reduces both noise and vibrations. Carriers are delivered as the ‘aggressive’ type, which reduces / eliminates slip during loading and ensures a more consistent log gap.

 

Acceleration conveyors

The acceleration conveyors are delivered with flat carriers and high power to enable log gap elimination into the debarking machine via active acceleration ramping between two or more conveyors.

 

Scan conveyors

The ability to accurately measure all log parameters is the basis for a modern and automated log management, which in the following steps allows a high recovery in the sawmill. Our scan conveyors are always delivered with proven sensor technology from experienced partners, which ensures qualitative information sharing to operators and the control system. For high precision requirements, Hedlund’s scan conveyors can be delivered with v-rail guided carriers that eliminate unwanted movements through the scan zone.

Kickers

Hedlund’s kicker range consists of three different designs for kicking logs from log conveyors. They together cover a variety of needs based on actual conditions and requirements. All solutions share our overall design philosophy of dimensioning for high quality and reliability in tough operating conditions. We also offer the possibility of retrofitting certain types of kicker systems to existing log conveyors of all makes.

 

Eccentric

This type operates with a kicker disc that rotates off-centred around a shaft in bearings powered by an angular geared motor. The eccentric movement results in a soft push on the log which, together with a continuous rotation direction without turning positions, results in reduced noise levels and reduced machine wear.

The kicker disc is suspended in a machined steel bearing housing with double row spherical roller bearings for high reliability. A rubber coupling dampens the gear from torque spikes for increased service life. This type of kicker can be mounted directly on the machine or to a separate frame to isolate it from the machine. The system is suitable for quick and easy retrofit to existing machines.

Separate drive on all units introduces additional degrees of freedom in the controls and therefore enables compensation for, as example, taper, which results in high precision in the push. Furthermore, each section allows mechanical adjustment of the home position for quick adjustment without touching the control system.

 

Bottom kicker – Direct drive

A classic in modern design – the bottom Cow Horn kicker. The kickers are mounted to a shaft in bearings and provided with direct drive from an electric gear motor. For one- or two sided discharge. Minimum no of moving parts and need for maintenance. Controlled via frequency inverter and brake resistor. Can be configured with optional number of kickers per drive and shaft depending on log length range and log gap. A typical configuration is ‘2 + 1’ for all lengths, even leading ends, i.e. two drives and shafts and in total three kicker arms.

 

Bottom kicker – Crankshaft drive

A Cow Horn kicker with crankshaft drive is the uncompromising alternative for bottom kickers with its soft turning positions enabling long service life under the absolute toughest of operating conditions.

Log elevator

Hedlund’s log elevators are custom fit to height, width and angle to always ensure optimal function. The chains run on Hardox® wear faces for long service life and are powered via a shaft mounted electric gear motor. Chain sprockets of split type with keyways for easy replacement. Chains tensioned individually or in pairs with separate tensioning devices. The machine is configured with different types of carriers for both indexed or semi-singulating applications.

Step feeders

The obvious choice for singulation and one-piece feeding of logs. Hedlund’s step feeders are nowadays almost exclusively delivered with electric crank shaft drive for soft turning and quiet operation. The electric gear motor is placed on the side of the machine for easy access and maintenance. The power transmission and adjustable roller tracks in heavy duty design are accurately machined for high precision, reliability and long service life under harsh operating conditions. As an option for the feeder steps, replaceable wear faces are available in Hardox®, to easily maintain the machine’s geometry over a long period of time.

 

Single action

Our single action step feeder can be delivered with 2 to 4 steps for small or normal logs. Peak capacity 35 strokes per minute with frequency controlled drive.

 

Double action

Our double action step feeder for small or normal logs. Peak capacity 60 strokes per minute for small logs and 40 strokes per minute for normal logs. The two step feeder units operates 180 degrees phase shifted so that dynamic balance is maintained throughout the work cycle, resulting in ultra-smooth operation.

 

IQAN proportional valve control

Upgrade kits for proportional valve control for existing hydraulic feeders. For increasing the feeder strokes up to 28 per minute. Delivered with a new set of control valves and a separate control system made by IQAN®.

Log ladder

The log ladder or log singlator is a machine which can handle high piece counts and singulate to one log at a time thanks to its geometric design. A log ladder can come with one, two or three steps depending on the application. The log ladder is often placed in after a log elevator.

Waste conveyors

In sawmill infeeds and log sorters it is inevitable that debris will fall out. Mainly bark will come off the logs when rubbing against other logs and machinery. It is important to clean and remove debris for reasons of well-being and safety. Debris will drop in different places. We have three different machines listed below that will safely clean all types of areas.

 

Belt conveyors

Belt conveyors come in different designs. The most common type is the idler roller conveyor which works well for bulk material handling. An idler roller conveyor can typically be used for bark and waste but also for chips and sawdust. It has high capacity, relatively low cost in relation to capacity, low need for maintenance and a low noise.

Trough belt conveyors are often used for overs return to the chipper.

 

Screw conveyors

Shaftless screw conveyors are modern, safe and cost efficient. They come in a number of sizes for different capacities and applications. Horizontal, vertical and any angle in between. Almost unlimited in length. Covered for safety and minimal dust emissions and spillage. The most modern way to design sawmill waste handling systems.

 

Scraper conveyors

Scraper conveyors are reliable, safe and cost efficient. They come in a number of widths for different capacities and applications. Horizontal and inclined in any angle up to about 60 degrees. Almost unlimited in length. Covered for safety and minimal dust emissions and spillage.

Log cross feeder

Log cross feeders are used in sawmill infeed applications, f.ex. as buffer or as storage deck in combination with curve turners. Also used as storage decks for batch infeeds. Chains with carriers for indexed feed or without carriers for max storage capacity.

 

Grading deck

Log grading on a cross feeder deck is excellent for visual grading. Thanks to low speed and the fact that logs will roll in front of the operator, more exact grading can take place. A grading deck consists of a log cross feeder with carrier chains, to keep logs in one space so it can bring its individual grading information to the sorting line. Logs can also be aligned on the grading deck with powered rollers. A mirror on the opposite side of the conveyor allows visibility on the opposite logs ends. Grading decks are combined into log sorting lines.

Log singulators

Log singulators are available in many designs for different applications. In common they all have the function of feeding logs one by one to a longitudinal conveyor in even intervals. Examples of log singulators are electrically powered star wheels and infeed arms. Log singulators are available as machine assemblies or as a machine parts adapted for individual applications.

Log decks

A log deck is what typically comes first in a log sorter or in a sawmill infeed. Log decks often come in two sections: one loading section and one thinning section. On the loading section, bundles of logs are placed with a loader or crane with grapple. The capacity of the log deck is primarily decided from the length of the log deck. The loading deck brings logs forward on its chain beams until reaching the thinning section. The thinning section is shorter but essentially of the same design as the loading section. The thinning section has its own drive. The chains move faster to break down the log bundle in a layer better suited to be handled by the following machine.

 

Log decks are designed among all to suit the plant’s capacity, log dimensions and means of loading.

Cleaning conveyors

Our cleaning scraper conveyors are designed for the toughest sawmill environment. Those conveyors are continuously running over large areas in all weather conditions. We use a high-grade wear resistant scraper steel moving along the conveyor trough bottom, bringing snow, ice and debris from the under deck area to the collection point. The scraper steel is subject to wear, but our modular design allows replacement of the scraper steel and wear parts, in order to extend its life over a long period of time. With optimized control and a clever sensor system, the system detects and self-compensates if a scraper is angled or if loads are greater than allowed to avoid breakdowns.

Metal detectors for logs

A metal detector for logs can be integrated in a log sorter or in a sawmill infeed. The metal detector consists of a round detector coil enclosing a metal-free belt conveyor. Logs are conveyed through the detector coil. If metal is detected, an alarm is triggered and a sequence for stopping the conveyor or kicking the log to a dedicated bin is started. The conveyor has a fibre glass trough in which a rubber belt is running. The belt is powered by a geared motor. In connection to the following conveyor, a driven diabolo roller re-positions the log to the centre line after the flat conveyor belt. The detector coil is mounted to its own frame to avoid vibrations and interference. The coils come in two sizes for max 650 mm and 800 mm logs.