Page 24 - Davenport Tooling Catalog

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Order:
586-465-5000
Fax:
586-465-3030
22
44725 TR INI TY DR I VE • CL INTON TOWNSH I P , MI 48038 USA • WWW. SLATERTOOLS .COM • D I RECT@SLATERTOOLS .COM
IMPORTANT:
Shave tool holders come equipped with large diameter roller and left hand offset type roller back rest, unless otherwise specified.
Roll Design
As nearly as possible, the roller should be over the center of the cut (refer to samples
at bottom of page). This is easier if a shop has on hand a variety of right-hand, left-hand and on-
center roll holders. There are numerous varieties of roll position, and each application calls for
a different usage.
When radiused surfaces are shaved, a straight, cylindrical roller will give only line
contact, and may leave a pressure mark. On the other hand, a roll contoured exactly like the
part may bind on contact with the unshaved surface. The best answer is shown in Figure 4,
where the radius of the roll is slightly greater than that of the part. In a concave situation, the
reverse would be true; the roll’s radius should be less than that on the workpiece.
In shaving a taper, rolls may skid, due to the differential between the various diame-
ters of roll and work piece. There are two logical solutions: (1) use split rollers side by side in
the same holder: (2) use one tapered roller in a tilted holder. While the second suggestion
calls for a specially designed roller back rest, it is generally the best.
Shaving Shoulders and Grooves
If the tool must work close to a deep shoulder, a stop device, like the one shown in Figure 5, controls the upward travel of
the tool and insures against tool-grabbing. As holder advances toward stock center, the tool digs into shoulder and body is raised to
an unsuitable clearance. This improper shaving condition will not allow roll to contact part and guide tool in its proper cutting path,
but rather allows tool to advance unguided. This will damage dovetail tool or break work piece. It is possible tool may raise holder to
a point where body would ram shank. If this happens, damage will occur to the shave tool holder. Note the stop nut limits travel, but
does not interfere with the float of the holder on the spring.
Actual jobs shaved with shave tool holders. Standard rolls and roller back rests may be positioned, and
adjusted to shave the contours of many parts usually associated with special rolls and roller back rests. Standard roller back rests
may be placed in any of 3 positions for both straddle and offset type roller back rests. (7/16 shave tool holder have 2 roller positions
only.) A combination of any 2 roller back rests may be used in the D-1 and D-3 positions for all shave tool holders. Tools are located
on the dovetail in the holder after part has been positioned for support by the roll. Special ground rolls are needed for tapered and
spherical surfaces. Extra wide roller back rests are made on order only. Undercuts, if not too deep (.010-.020) may be shaved in
without forming.
FIGURE 4
FIGURE 5