Patent Publication Number: US-2015083555-A1

Title: Position lock for electrical control devices

Description:
RELATED APPLICATIONS 
     This application is claiming the benefit, under 35 U.S.C. §119(e), of the provisional application filed on Sep. 20, 2013, under 35 U.S.C. §111(b), which was granted Ser. No. 61/880,471, and is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a position lock for electrical control devices. 
     BACKGROUND OF THE INVENTION 
     In a circuit breaker, or other electrical control device, the OFF state, TEST state, and ON state are quite important. For example, maintenance personnel often use a circuit breaker or other electrical control device to interrupt the flow of electrical energy through a circuit when the circuit, or electrical components connected thereto, require maintenance. The circuit breaker or other electrical control device, however, is often remote from the location requiring maintenance. Therefore, it is desirable to lock the position of the circuit breaker or other electrical control device to prevent an individual from inadvertently energizing the circuit while maintenance is being performed. 
     In draw-out circuit breakers and other electrical control devices, the ON state requires that the handle of the device be pushed in and turned in a specified position, whereas the OFF state requires that the handle be pulled out and turned to a different position. In order to safely lock a draw-out circuit breaker or other electrical control device in the OFF position so that maintenance workers can proceed with their work, it is desirable to have a lock that prevents the handle from being pushed in or turned. 
     Some circuit breakers or other electrical control device are manufactured to include a lock in the handle so that only a person with a key can change the position of the handle. However, this type of device has several drawbacks. First, it requires that the user has a correct, functional key in order to lock the position of the handle, which can be logistically difficult, especially in an emergency. Second, such a system of locks is only effective if all the electrical control devices are of the keyed handle type, which may require replacement of existing non-keyed electrical control devices which is costly. 
     Preferably, either a simple, inexpensive lock can be retrofitted onto existing electrical control devices or the people involved in maintenance of the circuit, or electrical components connected thereto, could carry a portable lock that can be used on electrical control devices commonly seen in their field of work. The embodiments of the current invention describe position locks that achieve both of these goals. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to position locks for n electrical control device, which are structurally simple, reliable, convenient to operate, and can prevent mis-operation, and lowers the costs for manufacturing, installing, and maintaining the device. 
     In accordance with one of the embodiments of the invention, a position lock for an electric control device would contain a mounting member; a pivoting member, and apertures for receiving a shackle of a padlock disposed within the pivoting member. The pivoting member can rotate along a single axis in relation to the mounting member. The pivoting member may be U-shaped and is of a sufficient length to be able to swing over handle of the electrical control device being locked. 
     In accordance with another of the embodiments of the invention, a position lock for an electric control device made from a tube that contains a slit and apertures for receiving a shackle of a padlock is described. The tubular lock may also have a notch for receiving the handle of the device being locked. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which: 
         FIG. 1  is a photograph of one embodiment of a position lock. 
         FIG. 2  is a photograph of the lock shown in  FIG. 1  as it would be mounted on an electrical control device and positioned to prevent the handle of the electrical control device from being turned when the lock is secured in place. 
         FIG. 3  is a photograph of the lock shown in  FIG. 1  as it would be mounted on an electrical control device and positioned to allow the handle of the electrical control device to be turned. 
         FIG. 4  is a photograph of an alternative embodiment of a position lock. 
         FIG. 5  is a photograph of the lock of  FIG. 4  as it would be placed on an electrical control device and positioned to prevent the handle of the electrical control device from being turned when the lock is secured in place. 
         FIG. 6  is a photograph of the lock of  FIG. 4  as it would be secured in place with a padlock. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In order to make the technical features, objectives, and efficacies of the present invention more comprehensible, a detailed description of embodiments is given below in conjunction with the drawings in which the same member has the same reference numeral. 
       FIG. 1  shows one embodiment of a position lock  10 . The lock  10  is comprised of a mounting member  12  and a pivoting member  14 . As shown, the lock  10  may have a pin  16  that attaches the mounting member  12  and pivoting member  14  to each other, although any means of attachment that allows the pivoting member  14  to move rotationally about one axis in relation to mounting member  12  is contemplated by this invention. If a pin  16  is used as the means of attachment between the mounting member  12  and the pivoting member  14 , the pin  16  will be disposed in pairs of apertures (not visible in these figures) in both the mounting member  12  and pivoting member  14 , where the pairs of apertures are aligned to receive the pin  16 . The mounting member  12  may have an additional aperture  18  through which a mounting screw (not shown) may be used to mount the lock  10  to an electrical control device (an example of which is shown as reference number  20  in subsequent figures). 
     As shown in  FIG. 2 , the pivoting member  14  should at least be of sufficient length to be able to swing over handle  22  of electrical control device  20  once the mounting member  12  is secured into place on the electrical control device  20 . The pivoting member  14  can be a U-shape, where, when in a locking position, the handle  22  of the electrical control device  20  is located within “U” of the pivoting member  14  of the lock  10 . Other shapes that allow for such an arrangement are also contemplated, such as a square or V-shape or the like. The lock  10  may be constructed from metal, wood, plastic, or any suitably rigid material, or any combination of suitably rigid materials. Suitably rigid means to be of sufficient strength to withstand being mounted on electrical control device  20  and to be of sufficient strength to support the shackle of a padlock being disposed in apertures  24 , as described below. 
     The pivoting member contains apertures  24  for receiving the shackle of a padlock used to further secure the handle  22  of the electrical control device  20 . When the shackle of a padlock is disposed within the apertures  24 , the shackle will effectively shorten the length of the pivoting member  14  so that the pivoting member  14  cannot be moved in such a way as to fully free the handle  22 . In other words, if someone attempts to move the pivoting member  14  during a lockout, the handle  22  and shackle will interfere with one another and prevent full release of the handle  22  from the pivoting member  14 , which, in turn, will prevent them from being able to push in and turn the handle to close the circuit. 
       FIG. 3  shows the lock  10  mounted on an electrical control device  20  in a disengaged or unlocked position. Here, the mounting member  12  is attached to the electrical control device  20  as in  FIG. 2 , but the pivoting member  14  is rotated around the pin  16  and is now in a disengaged or unlocked position. In this situation, the handle  22  of the electrical control device can be freely turned or pushed in or pulled out. 
     The benefits of this embodiment include that it is relatively simple and inexpensive to manufacture and relatively easy to retrofit onto already existing electrical control devices with the aid of a simple screw or other means of attachment. Once installed, use of the lock described in this embodiment only requires the user to carry their own padlock, or other means of securing the lock, for the lock to function. 
       FIG. 4  shows an alternative embodiment of a position lock to be used in accordance with the present invention. The lock  30  may be constructed from metal, wood, plastic, or any suitably rigid material, or any combination of suitably rigid materials. Suitably rigid means to be of sufficient strength to support the shackle of a padlock being disposed in apertures  34 . The lock  30  is a tube  32 . 
     The cross-section of the tube  32  is irrelevant, but as shown here the tube  32  is cylindrical. The lock  30  may be unitary or made from one or more parts joined together. When in place, the lock  30  must be of sufficient height to prevent the handle  22  of the electrical control device  20  from being pushed in and closing the circuit. 
     As shown in  FIG. 4 , the lock  30  has a slit  36  through one portion of the wall of the tube  32 . The slit  36  should extend through the entire length of the tube  32  and should be of a width that allows for the extending portion  38  (shown in  FIGS. 2 ,  3 , and  6 ) of the handle  22  of the electrical control device  20  to pass through the slit  36 . 
     As mentioned above, the lock  30  contains apertures  34  for receiving the shackle of a padlock used to secure the extending portion  38  of the handle  22  of the electrical control device  20  within the lock  30 . When the shackle of a padlock is disposed within the apertures  34 , the shackle will create a barricade between the extending portion  38  of the handle  22  and the slit  36 , so that the lock  30  is effectively incapable of being removed from the electrical control device  20  without removal of the shackle. Therefore, if someone attempts to push in the handle  22  during a lockout which might, for example, restore electricity to the circuit, the handle  22  and the lock  30  will interfere with one another and prevent the handle  22  from being pushed in and closing the circuit. 
     An additional level of safety can be added if the lock  30  is constructed with a notch  40  disposed in the edge  42  of the tube  32 . The notch  40  is designed to give the handle  22  a resting place when in a locked position, such that the handle  22  cannot be turned because the upstanding edges  44  of the notch  40  block the rotational movement of the handle  22 . The height of the upstanding edges  44  is not particularly relevant, but should not extend through the entire length of the tube  30  so as to create a slit. 
       FIG. 5  shows the lock  30  in place on an electrical control device  20 . The handle  22  is resting in the notch  40 . The extending portion  38  (not visible) of the handle  22  has been passed through the slit  36 . 
       FIG. 6  shows a different perspective of the assembly of lock  30  and electrical control device  20  of  FIG. 5 , with a padlock  50  securing the lock  30  in position. The shackles  52  of the padlock  50  pass through the apertures  34 , thereby creating a barricade between the extending portion  38  of the handle  22  and the slit  36 , so that the lock  30  is effectively incapable of being removed without removal of the shackle  52 . The design of the position lock  30  prevents the handle  22 , once in an OFF position, from turning or being able to be pushed in. 
     The benefits of this embodiment include that it is simple and inexpensive to manufacture. Also, it does not require any retrofitting and can be used with many commonly used electrical control devices. A maintenance worker need only carry the lock as described in the embodiment with a padlock and can proceed to work without much expense or logistical problems. 
     Although the term padlock is used throughout as an example of a way to secure the position locks of the invention in place, any suitable means for securing the position locks of the invention in place can substitute for a padlock. This might include cable ties or other types of locks other than padlocks. 
     In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiments. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.