초록 ▼

A system for reducing the initial force required to actuate a valve, preferably a rotary valve, from its fully closed position is disclosed. The system comprises an operating arm fixed to and rotatable with the valve stem. Disposed and rotatable about, but not fixed to, the valve stem is a spur gear

A system for reducing the initial force required to actuate a valve, preferably a rotary valve, from its fully closed position is disclosed. The system comprises an operating arm fixed to and rotatable with the valve stem. Disposed and rotatable about, but not fixed to, the valve stem is a spur gear with an operating lever affixed thereto. The force applied to the operating lever is transferred to the operating arm through a gear sector carried on the operating arm. During the initial actuation, the gear sector engages with and rotates about a latch pin to increase the force applied to the operating arm by the operating lever. During the remainder of the actuating movement, the gear sector is fixed relative to the operating arm so that the force applied to the operating lever is transmitted to the operating arm without any increase in force.

대표청구항 ▼

A system for reducing the force which must initially be applied to an operating lever to actuate a quarter turn rotary valve from the fully closed position, said valve having a valve stem projecting from a valve housing, said system comprising: a spur gear disposed and rotatable about, but not fixed

A system for reducing the force which must initially be applied to an operating lever to actuate a quarter turn rotary valve from the fully closed position, said valve having a valve stem projecting from a valve housing, said system comprising: a spur gear disposed and rotatable about, but not fixed to, said valve stem; an operating lever fixed to said spur gear for rotating said spur gear about said valve stem; a cylindrical latch pin fixed to said valve housing and disposed substantially parallel to said valve stem; an operating arm keyed to and rotatable with said valve stem and including a cylindrical gear sector pin disposed substantially parallel to said valve stem; a gear sector carried on said operating arm, said gear sector defined by first and second parallel sides connected by an arcuate side having gear teeth for engaging said spur gear, a latching side opposite said arcuate side and two radial sides connecting said arcuate side with said latching side, said gear sector including a cylindrical groove in said latching side corresponding to said latch pin and an elliptical bore in at least one of said parallel sides substantially parallel to said groove for receiving said gear sector pin whereby said gear sector is pivotable on said latching side about said latch pin so that rotation of said gear sector about said latch pin and said gear sector pin rotates said operating arm and said valve stem; and means operatively associated with said latch pin and said groove for locking and unlocking said operating arm and said gear sector so that in an unlocked position said valve stem is driven by said gear sector through rotation of said gear sector about said latch pin to rotate said operating arm whereby the force which must be applied to said operating lever is reduced and so that in a locked position said valve stem is driven by said spur gear through said gear sector and said operating arm which are fixed relative to one another.