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USNR's Horizontal Shape Sawing system solves many problems associated with traditional curve sawing machines, resulting in consistently accurate lumber sizing.

The HSS uses revolutionary "virtual pivot" technology allowing the gang to vary its pivot axis based on cant thickness.

Using conical chip heads reduces overfeeding while providing optimum surface finish and chip quality.

HSS machine advances were developed in cooperation with USNR's MillExpert optimization group, who optimized the first virtual pivot HSS at Hyne & Son in Australia and another at Yoshida in Japan.

Virtual pivot technology uses linear positioners to position the machine, dramatically reducing maintenance.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USNR HSS System - Next Generation Curve Sawing

The USNR Horizontal Shape Sawing (HSS) system is the next generation of curve sawing technology, designed to eliminate the many problems exhibited by traditional curve sawing machines.

TheHSS is designed to accommodate larger cants, up to 30” in width. It features single or double arbor configurations that provide up to 12” depth of cut, and conical side heads for optimum surface finish and chip quality. The floating load-bearing surface allows for a longer service life with dramatically reduced maintenance costs.

The system uses a chipper and gang combination along with sophisticated control systems to position and move the chip heads and the saws, which enables it to automatically achieve maximum recovery at high feed rates. When coupled with advanced MillExpert™ Cant Shape Sawing optimization software, you have an extremely powerful and flexible system that lets you get the maximum value from every cant.

Many of the problems with traditional curve sawing machines are solved by the HSS, including inaccuracies between the relative chipper and saw positions, control of the work piece during transition from chip heads to the saws, overfeeding, secure cant tracking, and accurate paths of curvature during transition, all factors that impact board sizing.

Many factors contribute to this success, including the use of conical chip heads, and a machine configuration that allows for a dense array of press rolls for secure control of the cants. Having complete control of the piece during processing is critical to achieve accurate curve sawing. Conical chip heads reduce overfeeding because the cutting forces are substantially downward rather than forward. With cylindrical chip heads, the cutting forces are with the flow and tend to snatch the piece and cause overfeeding. Any overfeeding or underfeeding will cause the curve paths to go out of alignment and deviate from the optimized curve sawing solution.

MillExpert™ Shape Sawing Cant Optimization Delivers Results MillExpert™ Shape Sawing Cant optimization software provides advanced curve sawing capabilities including surface feature recognition which allows cant characteristics such as width, length, taper, sweep, and surface roughness to classify user definable grades. Multiple grade zones are easily configured within the cant, allowing different products with different values, targets, and wane rules to be placed in specific areas of the cant. In addition, USNR has eliminated more than 90% of the traditional field wiring and reduced start-up costs with a revolutionary PLC system based on distributed I/O. Machine segments are pre-wired at the USNR factory to remote I/O modules that are mounted directly on the equipment, reducing customer electrical requirements and enabling complete system pre-testing prior to shipping.

Traditional curve sawing gangs intentionally coupled the chip heads and the saws as close as possible, but there was still a significant distance that introduced transition errors from the chipper to the saw. Because there was no mechanism to guide the chipped surface of the cant relative to the saws, it wasn’t possible to get a very precise cut on the saw. To counter those errors, a clean-up saw was used. Because the magnitude of error varies with amount of sweep, the sawn jacket boards would have inherent thickness variation problems.

USNR thought it was futile to attempt to predict the face made by the chipper going into the saw without an additional guiding device. The chipper module includes vertical anvils that, through precisely controlled articulation of the machine, remain in contact with the opening face at all times. Going downstream into the saws, a set of vertical guide rolls ensure precise control of the chipped surface of the cant relative to the saw. This enables the creation of exacting jacket boards without the use of a clean-up saw.

A revolutionary feature of the HSS system is the “virtual pivot” sawbox. USNR’s virtual pivot allows the sawbox to vary its pivot axis based on cant thickness, to optimally position the saws in the cut.

Other shape sawing manufacturers typically separate the pivoting and translating functionality into dedicated mechanisms. These structures require pins, bearings, cam followers and tracks to function, which require heavy maintenance to maintain sawing accuracy.

With USNR’s virtual pivot technology, the sawbox and motors are mounted on a simple base, and the whole mass is on air bearings. Three linear positioners precisely locate and orient the sawbox assembly anywhere in space. Wherever you want the machine rotated and positioned on the horizontal plane, there is some combination of strokes from the linear positioners that will achieve it.

The technology is called “virtual pivot” because it doesn’t have a single pivot point. The pivot point is continuously adjustable, which allows for ideal handling of multiple thicknesses. Depending on the thickness of a cant, the optimal point of rotation varies.

Recent installations of USNR’sHorizontal Shape Sawinclude Culp Lumber in New London, NC, Yoshida Lumber in Miyazaki-Ken, Japan, Bennett Forest Industries in Grangeville, ID , Hyne & Son in Tumbarumba, Australia, and Tolko in Lavington, BC. Please stay tuned for more details on the successes of these installations.

High-Speed Belt Tensioning Idler

USNR's Belt Tensioning Idler is a high-speed alternative to the needle bearing type idler used on high-speed planer infeed systems and any V or Poly-chain belt application that has tensioning idlers.

The unit uses a small diameter roll (about 4" x 3") that is very effective in high speed applications, and the deep-groove ball bearing design creates less friction with higher load ratings. Higher speed and higher load ratings add up to longer service life and less maintenance.

It is designed to fit a Browning adjusting tightener, and grease zerks on both ends provide easy access for maintenance.

The close-up image at right shows the deep groove ball bearings in blue, with the shaft in dark green. The pulley wheel itself is a round metal piece approximately 4" x 3" shown in light green. The Browning adjustable tightener is brown, with the grease zerks in silver.

 

NEW PROJECTS

 

 

 

USNR says Thank You to our customers for the new orders. We appreciate your continued loyalty and pledge to continue earning it!