Page 19 - SCHAUBLIN

Page - Seite
4.3

Adaptation and function of dead length collets (F type) A: Collet

B: Locknut

G H I J K
C: Spindle
D: Sliding sleeve

E: Compression spring

F: Compression tube

G: Guiding diameter

H: Slot

I: Clamping taper
F E D C B A
J: Contact face

K: Bore

Clamping principle for dead length collets

The collet is introduced into the sliding sleeve and fit against the compression spring. Screw the
locknut into the spindle to push the collet into its seat, putting it in its proper position. The clamping
taper fits against the sliding sleeve and the collet bore remains larger than the nominal collet diameter.
This system does not use a keyway to permit the use of a key to lock angular position of the collet.

Clamping and unclamping of work pieces

Under the pressure of the compression tube, the sliding sleeve taper fits against the collet taper. Upon
contacting with the nut face, the bore closes and wraps the work piece. The collet is still held in position
against the nut face. The very precise sliding sleeve diameter prevents the collet from moving sideways
in its seat. The guiding reduces the angular error and the radial runout of the work part. The radial slots
ensure the collet flexibility. The compression spring moves the sleeve backwards and maintains the
collet in the forward open condition. The clamping distance is limited by the space between the sliding
sleeve and the locknut. Correctly setting the clamping length prevents the collet from being crushed in
case of a closure without a work piece present. If the collet is crushed, slots against slots, it distorts and
may eventually break. The correct use and application of the collet results in a longer life.

Specificity

From a certain bore size up, the diameters are grooved to ensure a better clamping of the work piece
and to apply a greater clamping force. The softer the part to be machined is, the more the grooves will
increase the clamping force.

The forces generated by the collet depend on the axial clamping force. Lubricants, dirt and the type of
material clamped also influence the clamping of the collet. For clamping forces, refer to table 8.5. For
information regarding machining of collet seats see page 16.1 in the catalogue.

Copyright © 2022 SCHAUBLIN S.A., All Rights Reserved www.schaublin.ch 476-4800 Edition 06/2022