Valve stem operator

• US 3,889,924 A
• Filed: 12/03/1973
• Issued: 06/17/1975
• Est. Priority Date: 12/03/1973
• Status: Expired due to Term

• Current Assignee: Anatole N. Karpenko
• Original Assignee: Anatole N. Karpenko
• Inventors: Karpenko, Anatole N.
• Primary Examiner(s): Schwadron, Martin P.
• Assistant Examiner(s): Matthews, David R.
• Application Number:
  US05/421,146
• Time in Patent Office: 561 Days
• Field of Search: 251/248,249.5,250.5 74/2,89.15,89.2 192/.03,.07,.096,91R 185/4R,4A
• US Class Current: 251/249.5
• CPC Class Codes: F16H 2025/2068 Means for returning linear actuator to zero position, e.g. upon occurrence of failure by using a spring
• CPC Class Codes: F16K 31/53 with toothed gearing
• CPC Class Codes: Y10T 74/18832 including flexible drive connector [e.g., belt, chain, strand, etc.]

Abstract

A valve stem operator which is power driven in one direction by a motor through a clutch and is driven in the opposite direction by a clock spring when the clutch is disengaged. The valve stem is a threaded rod which is moved by a jack nut carried on a rotary drive arbor. The drive arbor is connected to the inner end of the clock spring and is also disengageably connected through a clutch to an air motor driven worm gear. With the clutch engaged, the air motor and worm gear rotate the arbor to move the valve stem while also winding the clock spring. With the clutch disengaged, the clock spring rotates the drive arbor to move the valve stem in the opposite direction. A clutch shifter mechanism moves the clutch into engagement with the air cylinder and is biased out of engagement by a stripper spring such that if control air is removed from the cylinder the clutch will disengage and the clock spring will shift the valve stem automatically.

Claims

1. A fail safe valve operator, comprising:

a valve body having a valve seat therein;

a valve member mounted in the valve body for movement toward and away from the valve seat to closed and open positions, respectively;

a valve stem connected with the valve member to move the valve member between its open and closed positions;

motor means operatively connected with the valve stem to operate it to one of said positions;

clutch means connected between the motor means and valve stem to selectively engage and disengage the motor means from the valve stem; and

spring means connected with the valve stem so that when said valve stem is operated to its said one position energy is stored in the spring means, and when said clutch means is disengaged to disengage said motor means from the valve stem, the spring means acts on the valve stem to return the valve member to its other position.

2. A device as described in claim 1, wherein said motor means includes a rotary drive means connected to move the valve stem, said spring means comprising clock spring means having one end attached to the drive means for exerting a rotary foRce thereon, whereby said clock spring is wound when the motor means is connected through the clutch means to move the drive means to move the valve member to its said one position, and when the clutch means is disengaged, the prewound clock spring rotates the drive means to move the valve stem to its other position.

3. The valve stem operator as described in claim 2 wherein said motor means is coupled to said clutch through a worm gear drive such that the clock spring cannot rotate the drive means when the clutch is engaged, even when the motor is not actuated.

4. A device as described in claim 2 and wherein said clutch has a selective clutch shifter mechanism which is powered by a fluid cylinder to engage the clutch and which is biased to disengage the clutch when the cylinder is deactivated.

5. A device as described in claim 1 and wherein said clock spring means includes a plurality of clock spring elements.

6. A device as described in claim 1 wherein said rotary drive means is coupled to said valve stem through a low friction ball jack nut.

7. A device as described in claim 1 and wherein said rotary drive means, clock spring means and clutch means are coaxially aligned around said valve stem.