Technology of watch production - part 47
Cam D, a bell cam , returns the cutter spindle to neutral position (Fig
ure 1 7 ).
Cam E , a bell cam, opens the collet, this being followed by ejection o f
the gear (Figure 1 9 ).
Cam F , a flat cam , s tops the machine in s emiautomatic operation and
is not active in automatic ope ration .
Cam G, a flat cam , controls the feeding m echanism in automatic oper
ation.
Cam H, a bell cam, feeds the blank into the collet from the loading
s tation.
Cam I , a bell cam, controls the disengagement of the auxiliary - s haft
clutch. This cam is integral with the one- turn claw clutch.
Cam
J,
a bell cam , c ontrols the engagement and disengagement of the
camshaft clutch.
Cam K, a flat cam, locks the auxiliary shaft in a definite position.
The m achine operates as follows : the cam A ,
.
through a lever sys tem ,
m oves the cutter slide in the horizontal plane . The cutter feed is spring
powered and controlled by a drop on the cam (see cycle diagram in Figure 2 0 ).
The retraction of the cutter from the work is cam -actuated (rise curve ) .
The s a m e cam A , through a lever s ystem, can move the cutte:r head als o
i n the vertical plane, the cutter slide being lowered by spring action.
Cam A can c ontrol either cros s - feed o r infeed milling, but not both si
multaneously.
The cutter is lowered in order to permit the indexing of the blank to the
next tooth. Cam B frees the index plate from the lockpin when the milling
of one tooth is ended and the retraction of the cutter has been accomplished.
C am C rotates the ratchet wheel by one tooth (through a lever s ystem ), the
lockpin enters the next slot on the index plate under the influence of a spring,
and the milling cycle is repeated.
When the wheel has been completely milled the index-plate gear (6 )
( z =
3 0 ) (Figure 1 8 ) has made a full revolution.
The gear (8)
( z =
6 0 ) meshed with gear ( 6 ) has c ompleted only half a re
volution and if the milling of the wheel is to be p erformed in one pas s , the
catch on gear ( 8 ) has two pins located diametrically opposite one another.
The catch disconnects the lever from cam I , which is a part of the one
turn clutch on the auxiliary s haft. The clutch is moved rapidly to the left
by springs located inside the body, and meshes with the claw clutch on
gear ( 1 0 ). The auxiliary shaft begins to rotate . If the milling is to be car
ried out in two passe s , the catch on gear (8 ) has only one pin, and the
auxiliary s haft is s tarted after a complete revolution of gear (8 ).
Cam D, through a leve r system , lowers the cutter spindle to neutral
position.
C am E , through the lever P , depresses the plunger passing inside the
working spindle (see Figure 1 9 ). The collet is opened by springs , and the
part is ejected by the plunger .
Cams G and H control the f e e d of the blank from the magazine t o the
feeding carriage, and from there to the collet. In the m9st recent model
the blanks are fed directly from the magazine into the collet.
A spring-loaded lever with its left arm in the slot in cam I is caused
by the ris e curve to draw the claw clutch to the right, thus disengaging the
clutch and stopping the auxiliary camshaft.
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