Abstract:
An apparatus for a lock out/tag out device that is a permanent attachment to a standard breaker box is disclosed. The device is designed to prevent movement of an electrical breaker handle to a closed position when the device is in use. The device also prevents locking a breaker in an on position, thereby lowering safety concerns. When the device is not in use, the device will not interfere with the operation of the breakers and stays conveniently attached to the breaker box. The device also allows storage of locking devices when not in use, thereby enabling personnel to perform a service procedure more efficiently.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims benefit of U.S. provisional patent application Ser. No. 60/637,899, filed Dec. 21, 2004, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     Embodiments of the present invention generally relate to a circuit breaker lock out/tag out (“LOTO”) device that is mounted to a circuit panel.  
         [0004]     2. Description of the Related Art  
         [0005]     For many years, safety concerns for operator and maintenance personnel servicing equipment in an industrial setting have been at the forefront of the particular industry and federal and state lawmaking bodies. The Occupational Safety and Health Administration (OSHA) has implemented regulations that require employers to safeguard personnel by locking out and tagging out electrical circuit breakers to prevent energization of equipment while it is being serviced. This procedure, when practiced, can prevent serious injury or death to personnel in the vicinity of the particular equipment.  
         [0006]     Prior art mechanical devices have been created to prevent movement of the toggle type switch or handle of a modern electrical circuit breaker in the open (off) or closed (on) position. The devices are in the form of clamshells, pins, or some type of moderately hard material that is shaped or designed to mechanically block the toggle from moving. These devices, when attached or put in position can then be stabilized with the use of a locking device, such as, a standard padlock, only permitting movement of the toggle when the padlock is removed and the installation or positioning steps are reversed. The prior art devices have serious drawbacks in that the devices enable locking a circuit breaker in a closed position, and the devices are not integral to the breaker box.  
         [0007]     Circuit breakers are designed to move or “trip” to the open position when an electrical current reaches a determined potential. Most standard breakers will “trip” even though the handle may be secured by a prior art device and the circuit protection will be enabled. While locking a circuit breaker in a closed position may be needed in some situations such as preventing vandals from flipping a breaker, this is not useful in an industrial setting. A machine may be damaged or personnel may be seriously injured if an operator is not able to de-energize the machine or sub-system at will.  
         [0008]     The prior art devices are also not integral to the breaker panel, existing as discrete devices. These devices are usually kept in a central location in a facility that maintenance personnel will have to retrieve when needed. Production quotas and schedules may prevent the personnel from retrieving the device if a minor repair or alteration needs to be performed. These devices may also be misplaced after use, which will add to the down time of the machine if the employee has to search for the device. Some of these devices are difficult to install and require special training to use.  
         [0009]     The lock out/tag out procedure has been in existence longer than the OSHA regulation and is a common-sense approach to servicing a machine. Maintenance workers may have good intentions and are often required to disable the energy source to the particular piece of equipment or subsystem that they intend to repair or alter. Production quotas or managerial pressures may force these workers to forego this basic safety step in order to get the machine back “on-line” if the LOTO device is not convenient.  
         [0010]     Therefore, there is a need in the art for a lock out/tag out device that is simple to use, cannot lock a breaker in the closed or “on” position, and is built in to the breaker panel for convenient use.  
       SUMMARY OF THE INVENTION  
       [0011]     The present invention generally relates to a lock out device for a circuit breaker mounted in a circuit breaker box, the circuit breaker having an operating handle to allow an operator to move the breaker between an open and closed position. The lock out device has at least one swivel plate rotatably coupled to the breaker box and movable between a first position that permits locking the operating handle in the open position, and a second position that allows movement of the operating handle to a closed position, wherein the at least one swivel plate rotates about an axis that is substantially orthogonal to the movement of the operating handle.  
         [0012]     In another embodiment, a lock out device is described for a plurality of circuit breakers mounted in a circuit breaker box, each circuit breaker having an operating handle movable between an open and closed position. The lock out device comprising an enclosure having a plurality of shelves, and a plurality of swivel plates mounted to the enclosure and movable between a first position that permits locking the operating handle in the open position and a second position that allows movement of the operating handle to a closed position.  
         [0013]     In another embodiment, a lock out device for a circuit breaker mounted in a circuit breaker box is described, the circuit breaker having an operating handle movable between an open and closed position. The lock out device comprises an engaging means to prevent movement of the operating handle to the closed position, a means for supporting the engaging means, said means to support coupled to the breaker box, and a means for securing the engaging means to prevent movement of the engaging means, wherein the means for securing is coupled to the means for supporting.  
         [0014]     In another embodiment, a method for servicing an electrically actuated machine or component is described, wherein the electrical actuation is controlled at least partially by a circuit breaker mounted on a breaker panel. The method includes the steps of providing the circuit breaker having a movable handle in a closed position, moving the handle to an open position, positioning a swivel plate coupled to the breaker panel to maintain the handle in the open position, positioning a restriction member in a perforation adjacent the swivel plate to maintain the position of the swivel plate, and servicing the machine or component. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.  
         [0016]      FIG. 1  is an isometric view of one embodiment of a lock-out device coupled to a breaker box.  
         [0017]      FIG. 2  is a side view of one embodiment of a lock-out device.  
         [0018]      FIG. 3  is a side view of another embodiment of a lock-out device. 
     
    
     DETAILED DESCRIPTION  
       [0019]     The present invention discloses a built-in lock out device configured for connection to a standard breaker panel with minimal installation. The circuit breakers as described herein are standard circuit breakers known in the art and industry, but may be any apparatus having an integral exposed member capable of movement in at least two positions-one of the positions may close an electrical circuit and the other position may open the electrical circuit. Examples include switches and toggles. The breaker locking mechanism is integral to the device, and cannot be lost or misplaced. The lock out device is also capable of not allowing a standard circuit breaker to be locked “on”, thereby preventing possible fire hazards, machine damage, or injury to personnel.  
         [0020]      FIG. 1  depicts a breaker box  100  with a built-in lock out device  110  attached. The breaker box  100  is a standard breaker box known in the art having a front panel  130  and a recess  140  in the panel  130  that is adapted to receive and house a plurality of standard circuit breakers  105 . The breaker box  100  may be mounted on or near a piece of machinery that it serves by providing electrical power at the will of the user of the machinery by actuating a protruding handle  107  of the breaker  105 . The lock out device  110  also contains a plurality of swivel plates  170  coupled to an extended member  104  that is part of a lockout assembly  165  that is coupled to the lock out device  110 .  
         [0021]     A frame  150  of the lock out device  110  is coupled to the breaker box  100 . The frame  150  has an opening or cavity  115  that is adapted to provide clearance for the breakers  105  and allow free movement of the protruding handles  107 . Each of the handles  107  is configured to provide one of two positions to the user. The handles  107  seen in  FIG. 1  are in an “off” or open position that transmits no electrical power to the machine or components it serves. The “on” or closed position  220  of the handle  107  is shown in  FIG. 2  in phantom and signifies a closed circuit denoting electrical power to the machine.  
         [0022]     The lock out device  110  may be attached to the breaker box  100  by experienced service personnel using appropriate fasteners such as, self drilling, self tapping screws  120  in the frame  150  of the lock out device  110 . The frame  150  is adapted to fit into the recess  140  and to allow free movement for the handles  107 .  
         [0023]      FIG. 2  is a side view of the breaker panel  130 . Shown is the frame  150  in relation to the breaker  105  with the handle  107  shown in an open position  210 . Also shown are the screws  120  through the frame  150  and the breaker panel  130 . An opening  115  allows access for the breaker  1   05  and is shown in the area adjacent the breaker  105 . Also shown is a first end  230  and a second end  232  of the frame  150  that will be described in detail below.  
         [0024]      FIG. 3  is a side view of a lock out assembly  165 . Shown is a swivel plate  170  that is pivotally mounted to the frame  150  by two hinge devices  174 . The frame  150  includes at least a shelf  179 , which is integral to, or otherwise coupled to, the frame  150 . In this embodiment, there is one swivel plate  170  for each breaker  105  or handle  107 . The swivel plate  170  may be fabricated from sheet metal and configured to have projections  173  on opposite ends that are adapted to mate with a full perforation  177  or a partial perforation  175  disposed in the frame  150 . The swivel plate  170  has an opening  172  that is adapted to receive the protruding handle  107  of the breaker  105  when it is in an open or “off” position. The swivel plate also has a chamfered edge  176  that is adapted to provide clearance for a break or bend  178  of the frame  150 . The bend  178  is adapted to provide increased mechanical strength to the shelf  179 .  
         [0025]     In reference to  FIGS. 1, 2  and  3 , the operation of the lock out device  110  will now be described. When the protruding handle  107  of the breaker  105  is in an “off” or open position  210 , a swivel plate  170  and its respective opening  172  will allow the swivel plate  170  to be pivoted to engage and secure the handle  107 , thereby holding the handle  107  and preventing movement of the handle  107  to position  220 .  
         [0026]     To prevent movement of the swivel plate  170 , a restriction member is inserted into one of the perforations  180  adjacent the swivel plate  170 . In one embodiment, the restriction member is a shackle  190  of a locking device  160 . The shackle  190  is placed into one of the perforations  180  formed through the shelf  179 , thereby preventing pivoting of the swivel plate  170  away from the handle  107 . Once the padlock  160  is in a locked position, service personnel can be assured that the breaker  105  will remain in an open position  210  until the padlock  160  is removed, and maintenance may commence. In another embodiment, the restriction member may be a lockout hasp that is known in the art. In another embodiment, the restriction member is a cable from a locking device known in the art to lock a plurality of breakers  105 . The cable is a size and material that prevents lateral movement of the swivel plate  170 , and is of sufficient length to be threaded through at least one of the perforations  180 . The cable itself is then locked to prevent removal of the cable from the perforation  180 , thereby preventing movement of the swivel plates  170  and the respective protruding handles  107 .  
         [0027]     The construction of the swivel plate  170  prevents securing the handle  107  when it is in a closed position  220  due to the absence of an opening  172  adapted to secure the handle  107  in the closed position, thereby preventing locking a breaker  105  in an “on” position  220 . This results in increased safety to any corresponding equipment or personnel by allowing an operator or bystander to open the circuit at will if a problem develops and the machine should be de-energized. The adjacent perforations  180  are in a spaced apart relation to the protruding handles  107 , thereby allowing free movement to the handle  107 . When the swivel plate  170  is not in use and the breakers  105  are in the closed or “on” position, the plate  170  may be positioned so as not to interfere with the handles  107  and secured by a restriction member as discussed above. This results in unfettered operation of the breakers  105  while providing convenient storage for the restriction members, such as the shackles  190  of the padlocks  160 .  
         [0028]     In one embodiment shown in  FIGS. 1, 2 , &amp;  3 , the lock out device  110  may be an enclosure  102  adapted to mount on a standard circuit breaker box, having a rectangular frame  150  with a first protrusion  152  on a first end  230  and having a second protrusion  162  on a second end  232 , the first and second protrusions  152 ,  162  being substantially parallel and perpendicular to the rectangular frame  150 . The protrusions  152  and  162  may also facilitate prevention of accidental tripping of the circuit breaker  105  by providing a guard for the handle  107 , thereby preventing the circuit breaker  105  from tripping due to bumping by personnel or other objects. A cavity  115  is disposed in the frame  150  between the first and second protrusions  152 ,  162  and is adapted to allow access to a circuit breaker  105  and its protruding handle  107 . At least one swivel plate  170 , having a body including a chamfered end  176 , and an opening  172  disposed through the body, is pivotally mounted adjacent the cavity  115  and the handle  107 . The at least one swivel plate  170  is substantially parallel to the first and second protrusions  152 ,  162 . The second protrusion  162  has a perforation  180  formed therethrough that is adjacent the swivel plate  170  and is adapted to receive the shackle  190  of a padlock  160 , thereby preventing movement of the swivel plate  170 .  
         [0029]     In another embodiment (not shown), a swivel plate  170  may be rotatably coupled to the face of the breaker box  100  adjacent a standard circuit breaker  105  without the need for a protrusion  152 ,  162  or a shelf  179 . The face of the breaker box  100  may be suitably formed to allow the swivel plate  170  to rotate about an axis that is substantially orthogonal to the movement of the protruding handle  107  of the circuit breaker  105 , thereby allowing the opening  172  of the swivel plate  170  to pivot and engage the handle  107  in the open position when used. The swivel plate  170  could then be secured by a restriction member holding means that could be formed integrally with, or coupled to the breaker box  100  face adjacent the swivel plate, thereby providing means to prevent further movement of the swivel plate  170  and providing a storage location for the restriction member.  
         [0030]     In another embodiment (not shown), a swivel plate  170  may be rotatably coupled to the face of the breaker box  100  adjacent a standard circuit breaker  105  above or below (or to either side in the case of a horizontally mounted circuit breaker) the protruding handle  107 , thereby allowing the swivel plate  170  to pivot in a substantially parallel relation to the movement of the protruding handle  107 . The swivel plate  170  could then be secured by a restriction member holding means that could be formed integrally with, or coupled to the breaker box  100  face adjacent the swivel plate, thereby providing means to prevent further movement of the swivel plate  170  and providing a storage location for the restriction member.  
         [0031]     While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.