Vise Compensates And Centers With One Turn

Recently, a plant manager (who chooses not to be identified for competitive reasons) needed a machine to produce threaded eyebolts. Thread sizes ranged from 1/2 inch to more than 1 1/4 inch in size. The weight of a part ranged from 2 ounces to more than 4 1/2 pounds. The eye ranged from 1 1/2 to almost 5 inches in diameter.

The company supplying the machine was Zagar Inc., a machine tool builder specializing in high-volume holemaking. The company has four main product lines: multiple spindle drill heads, CNC & air/hydraulic feed units, workholding (fixtures & collets) and drilling/tapping machines. The company may be best known for its "crank style" multiple spindle drill heads, which allow for close center distances, placing more rotating tools in a smaller area. Zagar machines are used in the automotive, aerospace, electrical, electronic, propulsion, off-road construction equipment, hydraulic, pneumatic and contract manufacturing industries.

The builder has provided equipment to produce or qualify holes in most ferrous and non-ferrous materials since 1937. The design of the machinery has resulted in the development of stand-alone modular component product lines.

Walter Zagar, vice president, said that while designing a drilling and tapping machine for threading this customer's forgings, his company needed a small vise with special characteristics. After searching unsuccessfully for a vise on the market, the company's engineers decided to build one.

The new vise needed to

Center the forging under the cutter
Compensate for surface conditions
Offer a small footprint for mounting
Be mountable on an index table in multiples of six
Clamp two forgings at a time
Resist torque inherent with producing a 2.00-inch thread
Provide ample chip clearance and easy cleaning
Be hand-operated, with potential for future automation
Be adaptable to existing vise jaws
Allow for minimum setup time
Be operator-friendly

The resulting vise met these criteria. Both jaws move with one turn of the crank. Thus, it can center and compensate with a single twist of the screw. The movable jaws easily handle two parts. They can be reversed to grip to inside cavities. The clamping area is just over 4 inches square on each side of the screw. It resists the torque, and the open design lets flood coolant wash chips away.

A simple hand crank closes the jaws. The crank can be removed, exposing a hex driver for future automatic operation. Existing jaws are easily mounted. Location is established by a simple key and stud design to hold the jaw in place. Quick changeover and easy chip removal make the vise operator friendly.

The vise fits on a small sub-plate for an index table. The machine was subsequently designed around a six-station concept.

For more information, please contact Zagar Inc. at (216) 731-0500, enter 101 at www.mmsonline.com to visit online showroom, or write 101 on RS card. Please note: This will be my last column. I have enjoyed sharing stories of the successes of our colleagues. But given the economic times we are working in, I need to concentrate on my core business. I may be writing articles in the future, so if you have ideas, please drop me a note. Thank you for allowing me to be a part of your monthly activities.