Locks – Special application – For control and machine elements
Reexamination Certificate
1999-08-06
2002-05-07
Barrett, Suzanne Dino (Department: 3627)
Locks
Special application
For control and machine elements
C070S178000, C070S221000
Reexamination Certificate
active
06382001
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. Nos. 440,714 (Lamb), 441,357 (Crowell), 1,154,389 (Fogalsong), 1,248,204 (Thomsen), 1,250,127 (Beers), 1,380,675 (Myers), 1,526,047 (Butterworth), 1,672,137 (Seng), 1,843,072 (Stone), 2,795,129 (Schoepe), 3,134,291 (Barry), 5,085,063 (Van Dyke). Additional patents were cited in the prosecution of the parent application from 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 manufacturers' 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, or operation. 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.
Of additional concern, especially in large facilities where multiple handles are in place, is the task of key management. A keyless lock removes the necessity of a key to unlock the handle, while still maintaining restricted access through a user-supplied padlock or other lock upon the surrounding cap.
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 keyed 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 is a keyless locking mechanism for use in a lockout device for preventing the rotation of a shaft from a first rotational position comprising a substantially cylindrical body for insertion into an opening in the lockout device, a bearing chamber horizontally disposed within the cylindrical body, a plurality of bearings, preferably two bearings, disposed within the bearing chamber, a spring positionally disposed between the bearings, and an activator slot disposed on the top of the cylindrical body. Preferably, the keyless locking mechanism further comprises a viewing aperture positionally next to the activator slot for determining operational engagement of the mechanism.
The invention is also a lockout device for preventing the rotation of a shaft from a first rotational position comprising a handle body, a gear rotatably supported by the handle body and fixed to the shaft, a core positionally fixed to the gear, and a keyless locking mechanism comprising a spring-bearing mechanism disposed within the top of the handle body. Preferably, the gear comprises a sprocket gear having teeth directed radially outward from the axis of the handle body. Alternatively, the gear comprises a ring gear having teeth directed radially inward toward the axis of the handle body. In a preferred embodiment, the spring-bearing mechanism is disposed horizontally within the keyless locking mechanism. Preferably, the bearings extent to engage indents of the gear teeth to positionally fix rotation. In a preferred embodiment, the lockout device comprises a ratchet wheel fixedly secured to the ring gear or sprocket gear, and a spring-based pawl mounted in the handle body lower end opening for selective engagement with the ratchet whereby when the handle body is not fixed with the ring gear or sprocket gear, the handle body may be rotated in one direction only. The lockout device preferably further comprises a second locking device selectively engageable with the handle body for blocking access to the first locking device when the second locking device is engaged. Preferably, the second locking device comprises an enclosure fitting around at least a portion of the handle body to cover the first locking device and selectively locked to the handle body by a padlock. Alternatively, the second locking device comprises an extension for receiving a plurality of personal locking devices selectively mountable on and lockable to the handle body.
A primary object of the present invention is to provide a simple, low-cost, highly reliable, compact, lockout device for use on a wide variety of rotatable shaft control devices, such as valves, regulators and the like.
Another object of the present invention is to provide a lockout device which when in the locked position will still allow the rotatable shaft to be rotated in one direction only, such as to close the setting of the shaft of the control device but not to allow opening of the control device.
Still another object of the present invention is to provide a lockout device that complies with the Occupational Safety and Health Administration requirements for plant safety.
Still one more object of
Lane James N.
Neeley Rocky E.
Baker Rod D.
Barrett Suzanne Dino
Neelchine Engineering, Inc.
Ownbey Nancy E.
Peacock Deborah A.
LandOfFree
Keyless lock for lockout device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Keyless lock for lockout device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Keyless lock for lockout device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2915127