Customized Diaphragm Chucks

Northfield is continually developing new products, custom designed to solve the most difficult workholding problems. 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.

SPECIAL DRIVESHAFT BALANCE FIXTURES These are custom chucks use a special expanding collet to center the drive shaft end, and (3) or (4) fingers go through the bolt holes, expand and face clamp.		MODIFIED MODEL DPH-400W Above are (4) model DPH-400W (4in. dia.) diaphragm chucks with special jaws and stops. The stops have (3) small "Air Detect" holes for part seating conformation. Air is pumped through these holes, and when the part rests on the stop, the air pressure rises tripping a pressure switch telling the machine to start machining. The (4) clover adapters have grooves for a CAM follower to snap into to orient the chuck when stopped. Up top is an (8) passage rotary union to actuate all four chucks independently. Please call for further explanation. These are mounted to a (4) spindle Theilenhaus machine.
SPECIAL MODELDPH-400 4" This is a Special DPH-400 4" Diaphragm Chuck that has all components coated with a super-thin coating of hard-chrome to protect it from corrosion. It is also set up with sideports and air-detect through the side of the axial locator as shown. This is used on an EDM machine.		CUSTOM DIAPHRAGM CHUCK This custom 3 x 3 diaphragm chuck clamps the powdered metal gears (11 tooth). The upper and lower jaws flex separately to ensure clamping on the pitch line of the tapered gears.
HIGH SPEED BALANCING CHUCK This fixture locates a universal joint using built in V-Blocks and (2) diaphragm jaws. The jaws and blocks center the work piece while 2 arms slide down to face clamp.		GEAR CHUCKS Advantages Include: - Accuracy from .00001 to .000010 - Pitch Line Chucks - Wire Cut Carbide Teeth - Gripover Pins - Totally Sealed - Helical or Straight Thooth
DIAPHRAGM CHUCKS Features Include: - Rotating or Stationary Diaphragm Chucks - Quick change thru-hole & coolant thru models - Standard Diaphragm Chucks from 3" to 18" - Custom specials for all workholding applications		DPH-600 DIAPHRAGM CHUCK This is a DPH-600 (6 inch diameter) Diaphragm Chuck used for superfinishing (grinding for accurate flatness and parallelism) on the outer faces of the customer’s parts. (not shown) This chuck incorporates a center part stop (axial locator) which can be changed out using a hex key.
10-IN. DIA. FACE CLAMPING CHUCK Special 10-inch diameter face clamping chuck with adjustable orientating pins and center mounted diaphragm plate to center work piece before two contoured fingers swing into position to face clamp aluminum pump housings for distortion-free boring at 4,000 rpm.		4-IN. DIA. CHUCK WITH SPECIAL JAWS Standard Northfield model DPH-400 with special jaws to grip small end of powder metal slipper shoe for hydraulic pumps. Jaws are cone shaped for tool to cut back face as well as front face of shoe.
4-IN. DIA. DIAPHRAGM CHUCK TO GRIP CIRCULATOR PUNP BEARING HOUSING Model DPH-400W 4-inch diaphragm chuck with special jaws and stop to grip circulator pump bearing housing in-between the ears on the root diameter. Four of the six jaws are used because there are 8 ears. The pins are contoured to compensate for clamping diameter tolerance and diamond coated for extra grip. The O.D. and bore are machined and the part is ejected with an internal air piston.		7-IN. DIA. CHUCK FOR SCROLL MILLING Special 7-inch extra power diaphragm chuck to grip cast iron compressor scrolls on drive shaft hub for finish milling of scroll walls and face. Eight chucks are mounted to a tombstone and are air open/spring clamp. Chucks have pull down action to pull scroll onto fixed stop for zero “Z” axis location. Jaws change out for two sizes of scrolls and repeat to 1/10,000 T.I.R.
7-IN. COMPENSATING DIAPHRAGM CHUCK Special 7-inch floating diaphragm chuck to drive work pieces for grinding between centers. The work piece is located by the male centers and the jaws float into position while gripping the O.D. compensating the eccentricity		DPH-400 GRIPPING VALVE BODY One of our customers needed to grind a bore concentric to a pilot diameter with an O-ring groove and be perfectly perpendicular to a face. Northfield supplied a model DPH-400, 1 micron T.I.R., totally sealed diaphragm chuck with special jaws and stop. The jaws grip the short pilot diameter and have positive pull back action holding the part on the precision ground fixed axial locator keeping the part concentric and square.
6-IN. DIAPHRAGM, WITH SPECIAL JAWS, STOP AND CHANGEABLE FIXTURES Northfield Precision offers a workholding solution for Chicago Dial Indicator, a leading American manufacturer of Electronic & Mechanical indicators. A Northfield 6in. 10,000 rpm totally sealed 1-micron T.I.R. diaphragm chuck with special jaws and stop were used to enhance and increase production of machining the two bores that guide the indicator rod. These bores must be perfectly in line for an accurate indicator. Two fixtures are used to hold the brass indicator housing before the fixture/housing is placed in the chuck. One side is machined, the fixture is turned over and the second side is machined. Alignment of 1/10,000 T.I.R. is achieved from bore to bore.		7-IN. DIAMETER, 8000 RPM DOUBLE DIAPHRAGM CHUCK Dana needed a chuck for their balancing machines to hold drive shafts by their slip yokes. Normally, balancing operations are performed at approximately 900 rpm, but Dana balances their parts at road conditions. High-performance vehicles such as stock cars and Formula 1 cars hit 200 mph with their drive shafts rotating at 10,000 to 12,000 rpm. Our solution consists of two separate diaphragm chucks built into one with two separate sets of jaws, mounted one in front of the other. This is done to accommodate the long thin shape of the part. With one set of jaws gripping the front of the piece and the other gripping the rear, the result is accuracy of 1/10,000 T.I.R. and repeatability to 50 millionths with extreme rigidity. The center mounted spline driver is a gauge quality piece of tooling to drive the shaft on rapid start and stop of the balance machine. To meet Dana’s safety standards, all of their chucks must be air opened and spring clamped to hold the part even if they lose air pressure during the balancing operation. The chuck must not exceed 45 lbs. in weight for easy handling by the operators.
DIAPHRAGM CHUCK Another “High Pressure” Challenge for Northfield. Allied Machine Company manufactures a line of spade drill inserts ranging in size from 3/8 inches to 4 inches in diameter. They asked Northfield to provide a workholding device that could accurately hold their drill inserts in positi9on during the finish grinding operation. Several factors made this a challenging assignment. The small drill inserts offered very little surface to clamp on, yet a very high clamping force was needed to hold them during the grinding operation. And of course repeatability was essential. A Z-axis clearance problem caused by the grinding wheel added another problem. And, as if that wasn’t enough, our design had to be able to function reliably in an abusive environment, filled with grinding grit. After much thought, Northfield’s engineering department came up with a solution to Allied’s “High Pressure” challenge. We supplied a special 7-inch diaphragm chuck with two jaws made of air hardening tool steel (60-63 HrC) that delivers up to 2,500 pounds of clamping force to the drill insert. The entire operation is repeatable to within 1/10,000th of an inch. The chuck is less than 2 inches high. This low profile, combined with the extended cone shaped jaws, solved the grinding wheel clearance problem. And finally, because it is a diaphragm chuck, it is completely sealed and has no metal-to-metal moving parts – a perfect solution for the grit filled environment of the grinding room.		MODEL DPH-5S Special 5-inch diameter diaphragm chuck, air open diaphragm clamp. Chuck has 8 sets of jaws that repeat to 1/10,000 when removed & replaced. 6 different stops mount to center of chuck for positive axial location. Jaws are alloy steel hardened to 58/63 Rockwell “C”. Chuck is counted to a special balance machine that finds the center of gravity of the cast turbine blades and drills a centering hole in that position. The part is now rotated about this center instead of machining weight off different areas for balance. • T.I.R. = 50 millionths • Axial – 0 • Cycle time 30 seconds
7-IN. DIAPHRAGM CHUCK Special 7-inch diameter counter-balanced diaphragm chuck with 3 pull down fingers. Jaws grip O.D. of C.V. joint while fingers pull it into the fixed axial stop for zero axial location. Chuck rotates 5 – 6,000 RPM to balance C.V. joint drive shafts. • T.I.R. = 50 millionths • Axial = 0 • Cycle time 60 sec.		SPECIAL 5-IN. DIAPHRAGM CHUCK This is a five-inch diameter diaphragm chuck used for very precise grinding or turning. The chuck features a one piece hardened and ground morse taper no. 5 adapter and a female morse taper no. 3 in the chuck face for stops and other tooling. The chuck features no metal to metal moving parts, an internal hammer to eject morse taper tooling, an changeable inserts that repeat to 50 millionths T.I.R.
SPECIAL 3-IN. DIAPHRAGM CHUCK 3M needed a chuck that repeated to 50 millionths and weighed less than 1.5 lbs. to check the efficiency of an electric motor that gets implanted in the body to pump an artificial heart. We made a 3 inch aluminum diaphragm chuck that weighs 1.40 lbs. and repeats to 40 millionths. 3M needed to remove the bearings of the motor so only the primary components could be tested for efficiency. To do this, the rotor and stator must be held in position as if the bearings were installed. To do this, a Northfield Model 350 - 50 millionths holds the rotor and rotates. The diaphragm chuck is mounted to a very sensitive torque meter that measures the torque created by the magnetic field of the rotor and stator.