Thread Rolling Machines: Standard Features
Infeed rolling utilizes a timed machine cycle. This is used for general rolling of parts up to the maximum die face width and also shouldered or headed work pieces.
In infeed rolling, the helix angle is ground into the dies. The work piece and the dies are kept parallel on the machine. The work piece rotates between the dies, but has little or no axial movement. By using a continuously timed cycle, production is greatly increased.
Thrufeed rolling is used for rolling threads which exceed the maximum length of the dies. It is also used for continuous rolling of long threaded bars or studs. In thrufeed rolling, the most commonly used die is the annular ring type. The thread form is ground on the die in straight rings with no helix. The helix angle is produced by tilting the spindles on the machine. Multiple start threads (within range of machine) can be rolled by increasing helix angle tilt on the machine. Multiple start high helix threads and worms can be rolled with helical slow feed dies where part of the helix is ground into the die and part is tilted on the machine spindles. Speed-up dies are used for high speed thrufeed rolling.
Both dies rotate in synchronism when rolling is being done. The work piece rides between the dies on a support blade. Size of work piece dimensions are controlled by a precision lead screw.
The hydraulic piston contacts a positive stop for each cycle, thereby producing identically sized work pieces.
A graduated feed dial and/or dial indicator is used to accurately set die penetration depth.
The Drive System
Various drive systems are available to suit the customers' needs: single speed, four speed, six speed, and infinite variable speed are available on most machine models. Some models of machines are available in thrufeed only models (no hydraulic feed). These models can be used for continuous rolling only.
The Hydraulic System
Hydraulic units are located on the side of the machine base. This facilitates cooling and easy maintenance. Rolling and return pressures are adjustable, as is speed of die penetration and retraction. The hydraulic systems are kept quite simple, utilizing a pressure compensated pump, a flow control and a directional valve. This means less maintenance.
All of our models incorporate drive shaft containment fixtures as a safety feature. A keylock switch on the control panel enables the operator to quickly lock out the spindle starter when making set-up adjustments. Micro switch interlocks on the drive shaft guards eliminate the possibility of starting the spindle when set-ups are being performed in this area and the guards are open.