Page 251 - Robot Builders Source Book - Gordon McComb

7.4 Feeding of Oriented Parts from Magazines 239

FIGURE 7.14 High-volume a) zigzag and
b) spiral hoppers.

FIGURE 7.15 Examples of vertical
sleeve, tube, or channel hopper.

drive the parts in the hopper pneumatically or with a spring. The latter is generally
used in automatic firearms. To be reliable, cut-off of the fed parts requires a certain
degree of accuracy in the mechanism. Thus, the gap A is restricted to a value of about
0.05 to 0.1 mm, the value ^ ~ h - (0.05 to 0.1 mm), and h ^ 0.5 mm.
Vertical box hoppers are more compact. Figure 7.16 illustrates several such hoppers.
Case a) consists of box 1 in which the blanks are loaded in several layers, tray 2, and
shut-off pusher 3 which takes the blanks out of the hopper by pushing along their axis.
Viewb) shows the cross section of this hopper, and here agitator mechanism 4 is shown.
The purpose of this mechanism is to prevent creation of a bridge of blanks which dis-
turbs their free movement towards the outlet. Case c) shows a similar hopper where

FIGURE 7.16 Vertical box hopper.
TEAM LRN