Chipping away at rental & commercial: Bear Cat’s newest midsize chippers target rental, landscape applications – utility equipment – Crary Bear Cat
Published in: Diesel Progress North American Edition,
Date: 3/1/2004
By: Dawn M. Geske
Crary Bear Cat, West Fargo, N.D., announced the addition of two engine driven towable chippers to its line of outdoor power equipment. Handling brash and branches up to 6 in. in diameter, the 74624 and 74628 chippers are designed to provide a maneuverable, mid-sized chipper option for the rental market.
The chippers are the right size for the rental market and have all the features expected in a chipper of this size, said Ross Johnson, sales manager at Bear Cat. The chippers were also developed for use by commercial landscapers and arborists, the company said.
The main difference between the two machines is the engine. The 74624 chipper is equipped with a two-cylinder, OHV, air-cooled Honda gasoline engine rated 24 hp. The 74628 chipper is powered by a Tier 2, three-cylinder, liquid-cooled Kubota diesel engine rated 28 hp. The Kubota engine is pack aged with a Kubota radiator mounted to the front of the engine.
The chippers include an automatic hydraulic feed which feeds brush and branches with up to 6 in. diameters into the chipper section. The live hydraulic feed system operates in an open loop with continuous flow provided by a Kubota gear pump that is belt driven in the 74624 chipper and directly driven off the flywheel in the 74628 modal. The belt driven pump has a 0.40 cu.in. displacement while the direct driven pump has a 0.494 cu.in, displacement. Both pumps drive a 45.6 cu.in. White Hydraulics gerotor-style motor.
Brush and branches are fed into the 36 in. wide by 33 in. high, cone-shaped feed chute that is covered by a noise-abating rubber flap. A 15 in. diameter variable feed roller with 10 knife blades b-cabs the branches through the base of the feed opening. “The wide feed opening, 6.5 in. tall by 13.5 in. wide, allows you to feed a lot of real brushy material, material that is very, hard to get started in a hydraulic feed machine,” said Johnson. “With this wide opening you are allowed to get that material into the feed roller, which pushes it into the disc.”
The roller has four hydraulic valve positions; two reverse (available at both ends), positive neutral and forward. Feed roller speed is controlled by an adjustable flow control. A 26 in. belt driven cantilever disc with four steel 3/8 in. chipping blades mounted in an offset pattern cuts the material into chip sized pieces and passes them through openings behind the disc. The chips are then blown through the 360[degrees] rotatable discharge chute by four paddies in the back side of the chipper disc. The cantilever disc design is superior for fibrous material, which greatly reduces wrapping, the company said.
Incorporated into the automatic feed system is Bear Cat’s Try-Again feed, which is designed to re-feed jammed branches into the feeder opening. A controller within the chipper monitors the pressure of the motor when feeding branches. If the motor’s pressure rises, indicating a jam, the controller senses it and the material is reversed back out from the feeder, repositioned and fed again automatically. “The material that you’re chipping backs away from the disc for a fraction of a second just to get away from the blades,” explained Arian Mathias, project engineer at Bear Cat. “This is so it won’t generate heat on the chipping blade and then once the disc rotor recovers to a set rpm, it begins chipping again.”
This occurs three times before the operator will have to intervene and manually reposition the branch, he added. The controller also monitors disc rpm, when the disc drops below a set rpm, the controller will stop the feed.
The exterior control panel incorporates FWMurphy gauges to monitor engine temperature and oil pressure. Both models are equipped with a throttle control lever controlling engine speed and the starting aid lever starts the engine in the up position and releases the drive belt for easier starting. The down position engages the belt for chipping. A key-operated accessory setting heats the diesel engine glow plug before starting the chipper in cooler temperatures, the company said.
The chippers are mounted on torsion angle Henchen axles with P215/ 75Rx15 pneumatic heavy-duty tread Carlisle tires and hauling hitch. The chippers have a fully enclosed steel engine compartment and 12 gal. fuel tank. They weigh 1850 and 2475 lb., respectively.
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