Locks – Special application – For control and machine elements
Reexamination Certificate
2001-03-27
2001-12-04
Gall, Lloyd A. (Department: 3627)
Locks
Special application
For control and machine elements
C070S178000, C070S221000, C070S422000, C070S424000, C070S455000
Reexamination Certificate
active
06324877
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention (Technical Field)
The present invention relates to safety devices for preventing tampering or accidental change of the manually set position of a rotatable shaft, such as the shaft on a valve or regulator that controls the flow of fluid.
2. Background Art
Present lockout devices are designed to lock the handle on a valve or regulator where the handle is part of the original valve or regulator supplied by the manufacturer. Typically in these lockout devices, an enclosure is formed around the handle with a padlock that locks the enclosure in place to prevent access to the handle thus preventing the rotational position setting of the handle from being altered either accidentally or out of ignorance or maliciousness. Other lockout devices show a lock assembly that is housed within a cast valve body that with the aid of a key controls rotation of the valve shaft.
Examples of such locks are shown in U.S. Pat. No. 440,714 (Lamb), U.S. Pat. No. 441,357 (Crowell), U.S. Pat. No. 1,154,389 (Fogalsong), U.S. Pat. No. 1,248,204 (Thomsen), U.S. Pat. No. 1,250,127 (Beers), U.S. Pat. No. 1,380,675 (Myers), U.S. Pat. No. 1,526,047 (Butterworth), U.S. Pat. No. 1,672,137 (Seng), U.S. Pat. No. 1,843,072 (Stone), U.S. Pat. No. 2,795,129 (Schoepe), U.S. Pat. No. 3,134,291 (Barry), U.S. Pat. No. 5,085,063 (Van Dyke). Additional patents were cited in the prosecution of the parent application, of which this application is a continuation-in-part.
The principal objection to all of the above-identified lockout devices is the complexity of the mechanism which causes problems in reliability, increased manufacturing cost, and thus an increased price. Furthermore, many of these lockout devices require that the valve or regulator body handle be specially cast so as to house the locking assembly. Accordingly, the locking device is part of the valve or regulator when purchased and each valve or regulator manufacturer may have different types of devices which prevents uniformity of a single lockout device used throughout a manufacturing plant. It would be highly desirable to have a lockout device that could be used for a wide variety of different manufacturer's valves or regulators so that plant personnel could be taught to operate a single type of lockout device even though valves and regulators from different manufacturers are used in the same industrial plant.
Additionally, the prior art does not address the problem posed to industrial plant managers attempting to comply with regulations of the Occupational Safety and Health Act (OSHA). In particular, in 29 C.F.R. § 1910.147, the regulations set forth the responsibility of a plant operator for the control of hazardous energy. These devices are typically referred to as “lockout/tagout” devices. The purpose, as set forth in the regulations, is to prevent the “unexpected energization or start-up of the machines or equipment, or release of stored energy that could cause injury to employees undertaking servicing and maintenance of machines and equipment in the plant.” According to the regulations, “lockout” requires the “placement of a lockout device on an energy-isolating device, in accordance with an established procedure, insuring that the energy-isolating device and the equipment being controlled cannot be operated until the lockout device is removed.” Such safety lockout device requires some personnel-controlled means for locking, such as a key- or combination-operated lock. The regulation further provides that safety lockout devices shall be standardized within the facility with respect to color, shape, or size.
An important feature of the safety lockout procedure is that the safety lockout device must be under the exclusive control of the authorized employee performing the servicing or maintenance. Accordingly, it is understood that compliance with these regulations will require that a safety lockout device has at least one key, or combination, that can be used only by the authorized service/maintenance person to override any other lockout device that otherwise may be applied to the energy-controlling device.
If it is desirable to have a lockout device to maintain a rotatable shaft in a fixed manual setting, during normal operation of the plant, there may be provided an “operations” lockout device that is available to the process control engineer, supervisor, or other employee responsible for establishing the settings on all energy-controlling devices. The OSHA or “service/maintenance” or “safety” or “personal” lockout device then must supercede this operations lockout device so that a second key or combination lock under the exclusive control of service personnel can be applied to prevent access to the operations lockout device.
SUMMARY OF THE INVENTION
The present invention comprises a lockout device for a rotating shaft, such as the shaft that controls the position or setting of a valve or regulator, to prevent any unauthorized personnel from changing the setting of the rotatable shaft due to a lack of knowledge as to why the shaft is set at a particular position, to prevent inadvertent rotation of the shaft to a new setting, or to prevent malicious resetting of the shaft to thereby change the flow of energy through the valve or regulator.
According to the invention there is provided a lockout device for use with an energy controlling apparatus having a rotatable shaft, such as a valve or regulator, the shaft being manually set at a desired position to control the flow of energy through said apparatus, and the lockout device selectively preventing further rotation of the shaft. The inventive apparatus comprises: a handle body and a central bore in said handle body comprising a shoulder; a first locking means mounted in said handle body; a second locking means comprising a lockout cap, and the cap comprising: a flat plate of generally similar configuration to the upper surface of the handle body and overlying said upper surface, said plate having an upwardly projecting cylindrical housing fixed thereto, said housing having a transversely extending opening; a shaft also having a transverse cylindrical opening, said shaft receiving in said upwardly projecting housing and including a shaft portion projecting downwardly through said plate and to which is affixed an eccentrically mounted locking collar receivable in the central bore of the handle body; whereby when the transversely oriented openings are aligned, the collar engages the shoulder in the central bore in the handle body so as to prevent the locking cap from removal so as to prevent access to said first locking means; and at least one lock with a bail received in said transverse openings. The lock with a bail may be a padlock with a bail received in said transverse openings so as when in the locked position, to prevent rotation of said shaft relative to said upwardly projecting housing of said plate, thereby preventing disengagement of said collar from said shoulder and preventing access to said first locking means. Or, the lock with a bail may comprise a scissors-like bail comprising a pair of pivotally connected arms each having at one end one half of a ring that is insertable in said transverse openings and at the other end an enlarged end portion with a plurality of holes which when the scissors-like bail is closed, with the ring end halves closed and engaged in said transverse openings, the holes in the enlarged end portions are aligned so that each hole may receive the bail of a separate padlock.
There is also provided a lockout device for use with an energy controlling apparatus having a rotatable shaft, such as a valve or regulator, the shaft being manually set at a desired position to control the flow of energy through said apparatus, the lockout device selectively preventing further rotation of the shaft, comprising: a handle body; a central bore in said handle body comprising a shoulder; a first locking means mounted in said handle body; and a second locking means for receiving a plurality of personal locking devices selectively
Baker Rod D.
Gall Lloyd A.
Neelchine Engineering, Inc.
Peacock Deborah A.
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