Specialty Applications Chucks

Northfield is continually developing new products, custom designed to solve the most difficult workholding problems for all metal, composite, ceramic and glass materials. Our engineers provide custom workholding solutions for internal/external, thin-wall/rigid, over the shoulder, and hundreds of other unique solutions to exactly meet each workholding requirement to bring gage block accuracy to your production pieces.

7-IN, DIA, FACE CLAMPING FIXTURE WITH A MODEL 470 2-JAW MOUNTED IN THE CENTER This is a face clamping chuck that has a standard Northfield model 470 mounted in the center to locate a transmission component on the root diameter while the fingers swivel into position and face clamp. The air chuck gently centers the part with no distortion while the fingers face clamp for grinding.		MODEL 620THS CHUCK This is a standard model 620THS (Thru Hole Stationary) with special jaws to grip 1in. diameter. This chuck uses side ports because it does not rotate.
MODIFIED MODEL 425 This is a modified Model 425 (.0001 T.I.R.) air chuck. The work piece is loaded onto the chuck, sprocket side down. The sprocket face is used for axial location. Spring pins mounted in the locator, pickup 3 teeth in the sprocket to orient a timing hole on the backside to 45.648 degrees for finish machining. Hardened and ground top jaws are used to grip a 43.3mm internal diameter towards the top of the work piece.		SPECIAL FIBER OPTIC CANES CHUCK This is a special chuck we made for Corning to mount on special spindles to hold fiber optic “canes”. The canes can be up to 2.00 inch in diameter and must pass thru the chuck. Two chucks hold the 6ft cane (one on each end) and two additional chucks hold the “handle” that gets welded onto the ends of the cane. These chucks are lever-actuated via a fork (not shown) that pushes and pulls the groove-shaped collar at the bottom Of the chuck to open and close the jaws. These chucks have lower accuracy, but extended stroke to (1in.)accommodate the range needed for the operation. Each subjaw shown has an Insert Pad mounted within that contains special Celazole plastic material that can repeatedly withstand temperature up to 600°F during the heat fusing process. accommodate the range needed for the operation. Each subjaw shown has an Insert Pad mounted within that contains special Celazole plastic material that can repeatedly withstand temperature up to 600°F during the heat fusing process.
SPECIAL MODEL 470 CHUCK These are a couple of Model 470 chucks we retooled for Caterpillar. The part (shown being gripped in oneof the chucks is a “Wheel Poppet Adapter”. This chuck has special serrated insert pads to securely grip the part during the operation where they are drilling the holes on the side of the part. (The chuck is mounted on an indexing head to expose the side of the part for drilling). The plates attached to the sides of the jaws are used as a datum for drilling; one plate (best seen in the upper-left hand view) flexes to push the part such that it maintains positive contact against the solid Plate on the opposite side. The chuck also has an axial locator mounted in the center with line contact so as not to influence the grip of the part, but acts as a secondary datum.		PITCH LINE CHUCK MODEL 1000 This Pitch Line chuck grips the O.D. of 9 diameter helical gears. The pins are mounted in a loose fitting housing so they can float. The pins pick up the pitch diameter and the jaws grip the O.D. of the pins. The pitch is measured over pins, so we are gripping the same way they measure. This model 100 (10”dia.) chuck has two pin cages, one for a left hand helix and one for a right hand helix. The pin cages are changed out by removing (3) mounting screws.
6-INCH DIA. PULL DOWN FIXTURE This is a pull own clamp fixture. The part is a Bosch jig saw housing. Two pins mounted to chuck face locate the part and two face clamps rotate 90 degrees into position and come down to clamp the part. Fixture rotates at 3,500 RPM to bore a bearing nest.		SPECIAL MULTI-ACTION 5 1/2-IN. DIA. PULL DOWN FIXTURE SPECIAL MULTI-ACTION 5 1/2-IN. DIA. PULL DOWN FIXTURE
MODEL 450 Chuck has rubber boot and stainless steel shroud to hold boot in place at high RPM. Boot seals check against coolant, dirt & grinding grit. Chuck has sub-jaws and brazed carbide changeable inserts that repeats to 1/10,000. Axial locator has brazed carbide changeable stops. Customer grinds glass discs at 3,000 RPM on Wasino Lathe. • T.I.R. = 1/10,000		MODEL 700 Chuck is modified with 3 pull down fingers. Jaws have counter balance sub plates so jaws maintain 100% jaw force up to 6,000 RPM. Chuck is air open & spring clamp. Pull down fingers are independent. Chuck grips C.V. joint drive shafts, centers C.V. with jaws & pulls it down with fingers onto fixed stop. Shaft is balanced at 5-6,000 RPM. • T.I.R. – 1/10,000 • Axial – 1/10,000 • Cycle time 60 seconds
MODEL BIG RED No, we’re not making a fashion statement for chucks here! At Northfield, we affectionately refer to the aluminum anodized chuck as “BIG RED” (it’s anodized red). “BIG RED” is used by sub contractor Creed Monarch to manufacture close tolerance parts for Robert Bosch Power Tools. We designed “BIG RED” to accommodate the unusual shape of the “Wobble Plate,” part of the drive mechanism of a Bosch reciprocating saw. The “Wobble Plate” is made from 52100 tool steel, heat-treated to 58/63 Rc. It is then spun to 3,500 rpm for hard turning the “Wobble Plate” ID which is in reality the outer race of a bearing set. “BIG RED” is yet another example of custom application “beyond the chuck.” Its spring-loaded plunger and locator ensure accurate locating of the “Wobble Plate” to four specific reference points or surfaces (see photo). When hand mounted on the face of a fixture, the unique design and accuracy of the fixture provide repeatability of 0.002 inches. “BIG RED” solved the previous holding problems and in addition, saved a tremendous amount of production time, since the fixture allows automatic operation after the initial hand loading.		PULL DOWN CHUCK Special Drawbar-Actuated, Pull Down Chuck with Centered Pilot Here is a great example of how Northfield’s creative engineering helps customers solve tough workholding problems. When a special chuck was needed to hold an unusually shaped automotive part, Northfield was asked for ideas. The machining operation was basic, hard turn a straight bore that is case hardened to 58/63 Rockwell “C”. The complicating factor was the shape of the part; it was not round or concentric. The straight bore must be machined concentric to a cone shaped hub and perpendicular to a larger offset rectangular flange. After reviewing the problem, Paul DeFeo, Chief Engineer at Northfield, realized that the most accurate way to hold the part was to grip it by the cone and bank off the flange. The question was how, since the cone surface was too steep to be gripped by conventional chuck jaws. The solution was to design a special drawbar-actuated, pull-down chuck with a spring- loaded funnel shaped base that was a female version of the cone shape on the part. This base fits into the chuck body with a zero clearance sliding fit. The operator pushes the part down into the funnel, two spring loaded ball plungers hold the part in place, allowing the operator to move his hands away from the work area before activating the chuck. Upon actuation, clamping arms swing over and down onto the part’s flange. The spring loaded funnel base picks up the cone for centralization and slides into the chuck as the flange comes to a fixed stop for axial location and clamping. After machining, the arms retract and the part is pushed up and out for easy removal. How is this “not just chucks” approach working? Using our chuck, this application runs 24 hours a day, seven days a week, producing parts with outstanding accuracy and repeatability