| 摘要 |
<p>A pneumatically operated press in which the moving press plunger (13) is actuated by a toggle linkage (20, 21, 22) which is itself actuated by a second toggle linkage (30, 31, 32). The end link (31) of this second linkage is actuated by a large diameter pneumatic ram (34) while the pivotal point (32) of this second toggle linkage is connected to a relatively small diameter pneumatic ram (36), or some other actuator. An automatic switch (42, 32) engages a valve to admit air to the larger ram (34) when the smaller ram (36) has moved the second toggle (30, 31) into an in-line position. The ram (36) may be replaced by a manual operating lever.</p> |
