Patent Publication Number: US-11037740-B2

Title: Switch lockout device

Description:
BACKGROUND 
     Many switches, such as, for example, circuit breaker switches, are designed to be manually switched between two positions (for example, an “on” position and an “off” position) by a user. A circuit breaker switch may be configured to reset certain functions of the circuit breaker when the switch is toggled to the “on” position. Switches are commonly located in areas that are publicly or widely accessible. In many situations, accidental, innocent or unauthorized switch position changes can cause safety hazards, damage equipment or cause lost production time and/or in-process material losses. 
     SUMMARY 
     The present application describes devices and methods which may be utilized for preventing unauthorized or accidental movement of a switch, for example, between first and second toggle positions. In one embodiment, a lockout device is configured to be used with a switch assembly including a fixed base and a toggle switch moveable between first and second switching positions and disposed between first and second end walls extending to an outer surface of the fixed base. 
     Accordingly, in an exemplary embodiment, a lockout device for a switch assembly includes a body defining a bottom surface and a recess extending inward from the bottom surface to receive a toggle switch, first and second clamping portions disposed on first and second longitudinal sides of the recess, and an adjustable cleat member secured with the body and movable between a retracted position in which the cleat member is retained inward of the bottom surface of the body and an extended position in which the cleat member extends beyond the bottom surface of the body. 
     In another exemplary embodiment, a lockout device is provided in combination with a switch assembly including a fixed base and a toggle switch moveable between first and second switching positions and disposed between first and second end walls extending to an outer surface of the fixed base. The lockout device includes a body defining a bottom surface engaging the outer surface of the fixed base of the switch assembly, a recess receiving the toggle switch, a first clamping portion disposed in the recess and in engagement with a first side of the toggle switch, and a second clamping portion disposed in the recess and in engagement with a second side of the toggle switch opposite the first side. The second clamping portion is adjustable between a clamping position for securely clamping the toggle switch between the first and second clamping portions and a releasing position permitting withdrawal of the toggle switch from the recess. A cleat member is secured with the body and movable between a retracted position in which the cleat member is retained inward of the bottom surface of the body and an extended position in which the cleat member extends beyond the bottom surface of the body such that the cleat member is engageable with the second end wall of the switch assembly to prevent movement of the toggle switch to the second switching position. 
     According to another exemplary embodiment of the present disclosure, a method is contemplated for securing a switch assembly including a fixed base and a toggle switch moveable between first and second switching positions and disposed between first and second end walls extending to an outer surface of the fixed base. In the exemplary method, the toggle switch is placed in the first switching position. A lockout device is provided, including a body defining a bottom surface and a recess extending inward from the bottom surface, first and second clamping portions disposed on first and second longitudinal sides of the recess, and an adjustable cleat member secured with the body. The lockout device is assembled with the switch assembly such that the toggle switch is received in the recess between the first and second clamping portions, the adjustable cleat member is in an extended position and disposed between the toggle switch and the second end wall, and the bottom surface of the body engages the outer surface of the fixed base. At least one of the first and second clamping portions is adjusted to clamp the toggle switch between the first and second clamping portions. The adjustable cleat member is engageable with the second end wall of the switch assembly to prevent movement of the toggle switch to the second switching position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features and advantages of the invention will become apparent from the following detailed description made with reference to the accompanying drawings, wherein: 
         FIG. 1  is a side schematic cross-sectional view of a lockout device assembled with a switch assembly to prevent actuation of the switch assembly, according to an exemplary embodiment of the present disclosure, shown with the toggle switch in a first limit position; 
         FIG. 2  is a side schematic cross-sectional view of the lockout device and switch assembly of  FIG. 1 , shown with the toggle switch in a second, non-actuated position, limited by a stop portion of the lockout device to prevent movement of the toggle switch to an actuating position; 
         FIG. 3A  is a side schematic cross-sectional view of the lockout device of  FIG. 1  assembled with a switch assembly dimensionally different from the switch assembly of  FIG. 1 , such that the stop protrusion of the lockout device does not prevent movement of the toggle switch to an actuating position; 
         FIG. 3B  is a side schematic cross-sectional view of the lockout device of  FIG. 1  assembled with the switch assembly of  FIG. 3A , with an adjustable cleat in an extended position to secure the switch assembly in a non-actuated position; 
         FIG. 4  is an upper perspective view of a switch lockout device, according to an exemplary embodiment of the present disclosure; 
         FIG. 5  is a lower perspective view of the switch lockout device of  FIG. 4 ; 
         FIG. 6  is a side view of the lockout device of  FIG. 4  assembled with a switch assembly to prevent actuation of the switch assembly, shown with the toggle switch in a first limit position, with a portion of the lockout device body removed to illustrate additional features of the lockout device; 
         FIG. 7  is a side view of the lockout device of  FIG. 4  assembled with the switch assembly of  FIG. 6 , shown with the toggle switch in a second, non-actuated position, limited by a stop portion of the lockout device to prevent movement of the toggle switch to an actuating position, with a portion of the lockout device body removed to illustrate additional features of the lockout device; 
         FIG. 8  is a side view of the lockout device of  FIG. 4  assembled with a switch assembly dimensionally different from the switch assembly of  FIG. 6 , such that the stop protrusion of the lockout device does not prevent movement of the toggle switch to an actuating position, with a portion of the lockout device body removed to illustrate additional features of the lockout device; 
         FIG. 9  is a side view of the lockout device of  FIG. 4  assembled with the switch assembly of  FIG. 8 , with an adjustable cleat in an extended position to secure the switch assembly in a non-actuated position, with a portion of the lockout device body removed to illustrate additional features of the lockout device; 
         FIG. 10  is a side schematic view of another switch lockout device; and 
         FIG. 11  is a side schematic view of another switch lockout device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The Detailed Description of the Invention merely describes preferred embodiments of the invention and is not intended to limit the scope of the disclosure in any way. Indeed, the invention as described by the specification is broader than and unlimited by the preferred embodiments, and the terms in the specification have their full ordinary meaning. 
     The present disclosure contemplates lockout devices for securing a toggle switch of a switch assembly (e.g., a circuit breaker switch) in a desired position. As shown in  FIG. 1 , a conventional switch assembly  10  includes a fixed base  11  and a toggle switch  15  moveable between first (e.g., off) and second (e.g., on) limit positions between first and second end walls  12 ,  13  extending to an outer surface  14  of the fixed base. For a conventional circuit breaker switch, while the first and second limit positions are understood to be the “on” and “off” positions of the toggle switch, there is an intermediary actuating position (designated by axis A in  FIG. 1 ) between the first and second limit positions at which the circuit load is reset, which may, but need not, coincide with an intermediary actuating position at which the circuit load is shut off. Therefore, in some embodiments, a switch lockout device does not necessarily secure the toggle switch in the limit position, but rather blocks movement of the toggle switch to the actuating position. 
       FIG. 1  schematically illustrates an exemplary lockout device  100  assembled with the switch assembly  10  to prevent movement of the toggle switch  15  to the actuating position A. The exemplary lockout device  100  includes a body  110  defining a bottom surface  111  and a recess  112  extending inward from the bottom surface to receive the toggle switch  15 . A first clamping portion  120  is disposed on a first longitudinal side of the recess  112  and a second clamping portion  130  is disposed on a second longitudinal side of the recess opposite the first longitudinal side. An adjusting mechanism  140  is assembled with the body  110  and operable for longitudinal adjustment of the second clamping portion  130  to securely clamp the toggle switch  15  between the first and second clamping portions  120 ,  130 , and to release the toggle switch to permit removal of the lockout device  100  from the switch assembly  10 . A lockout arrangement  150  may be provided to prevent operation of the adjusting mechanism  140 . For example, a lockout arrangement may secure the adjusting mechanism against movement, and/or may block access to the adjusting mechanism. In the illustrated example, the lockout arrangement  150  includes a cover member  151  that blocks access to the adjusting mechanism  140 . The cover member may be secured in a lockout position by a padlock or other locking component, as described in greater detail below. 
     To prevent movement of the toggle switch  15  to the actuating position A, the bottom surface  111  of the body  110  includes a stop portion or fixed cleat, shown in the exemplary embodiment as a protrusion  113 , that extends past the outer surface  14  of the switch base  11  to engage the end wall  13  of the switch assembly  10 , thereby blocking further movement of the toggle switch  15 . While the protrusion  113  may engage the end wall  13  when the toggle switch is in the limit position, in some embodiments (i.e., in some switch/lockout device combinations), the toggle switch  15  with the assembled lockout device  100  may have a limited range of movement between the limit position and engagement of the protrusion  113  with the end wall  13 , while still preventing movement of the toggle switch to the actuating position A. 
     Switch assemblies have a variety of dimensions, including a variety of ranges between switch limit positions. As a result, a lockout device having a stop protrusion preventing actuation of a switch assembly with a more limited stroke toggle switch may be ineffective in preventing actuation of a switch assembly with a larger stroke toggle switch.  FIG. 3  schematically illustrates the lockout device  100  of  FIG. 1  assembled with a dimensionally different switch assembly  10   a , having a toggle switch  15   a  with a greater range of motion between the first limit position and the second limit position. As a result, the protrusion  113  engages the second end wall  13   a  at a position beyond the actuating position A, rendering the lockout device  100  ineffective for securing the switch assembly  10   a  against actuation. In contrast, a lockout device having a stop protrusion positioned to prevent actuation of a switch assembly with a larger stroke toggle switch may not fit onto a switch assembly with a more limited stroke toggle switch. 
     According to an aspect of the present disclosure, as schematically shown in  FIGS. 1-3B , the switch lockout device  100  may be provided with an adjustable stop or cleat  160  that may be extended from the bottom surface  111  of the lockout device body  110  (as shown in  FIG. 3B ) to provide an alternative stop position for assembly with dimensionally different switch assemblies having different toggle switch strokes or ranges of motion. When the switch lockout device  100  is assembled with a first switch assembly  10  for which a protrusion  113  or other portion of the body engages the switch end wall  13  to prevent actuation, as shown in  FIG. 1 , the adjustable cleat  160  may be maintained in a retracted position, for example, to prevent interference with installation of the lockout device  100  on the switch assembly  10 . When the switch lockout device  100  is assembled with a second switch assembly  10   a  for which the body protrusion  113  does not engage the switch end wall  13   a  to prevent actuation (as evident in  FIG. 3A ), the adjustable cleat  160  may be moved to an extended position, as shown in  FIG. 3B , in which the cleat engages the switch end wall to prevent actuation. The cleat  160  may be adjustable on the lockout device body  110  using a variety of suitable arrangements, including, for example, a pivoting arrangement, a slidable arrangement, a ratcheting arrangement, or a threaded arrangement. 
       FIGS. 4-9  illustrate an exemplary lockout device  200  for securing to different switch assemblies (e.g., switch assemblies  10 ,  10   a  as shown in  FIGS. 6-9 ) to prevent movement of a toggle switch to an actuating position. The exemplary lockout device  200  includes a body  210  defining a bottom surface  211  and a recess  212  extending inward from the bottom surface to receive the toggle switch. While many different types of toggle switch receiving recesses may be utilized, in the illustrated embodiment, the body  210  includes a perimeter wall  215  surrounding a central opening recess  212  sized to accommodate toggle switches having a range of widths, lengths, and thicknesses. 
     In the illustrated embodiment, first and second clamping portions  220 ,  230  are disposed on opposite first and second longitudinal sides  212   a ,  212   b  of the recess  212 . The first clamping portion  220  includes a plate  221  that is secured to the bottom surface  211  of the body  210  (e.g., by fasteners  222 ), with a forward edge  223  positioned to grip a first side of a toggle switch. As shown, the forward edge  223  may be V-shaped to facilitate gripping or biting engagement of the toggle switch. In other embodiments, the forward edge may additionally or alternatively be serrated or toothed (not shown) to facilitate gripping or biting engagement with the toggle switch. The plate  221  may be removable and/or adjustable on the body (e.g., by adjusting the fastener in a slot in the plate), for example, to improve gripping engagement with a particular toggle switch. In other embodiments, other types of clamping members may be used, including, for example, knurled pads, or integral surfaces of the body. The second clamping portion  230  is defined by an end surface  231  of an actuating bolt  240  installed through a threaded bore  214  intersecting the second longitudinal side  212   b  of the recess  212 . The bolt  240  is threadably adjustable (e.g., by turning the head  244  of the bolt using a tool or by hand) in the bore  214  for longitudinal adjustment of the clamping portion  230 . The bolt head  244  may be knurled (not shown) to facilitate user grasping and turning of the bolt  240 . In other embodiments, other types of clamping members and/or actuating mechanisms may be used, including, for example, knurled pads, plungers, or ratcheting bolts. In one such example, an adjustable bolt may be configured to drive a separate clamping member, such as a knurled pad. 
     In the exemplary embodiment, a lockout cover  250  is hingedly connected with an upper flange portion  216  of the body  210  (e.g., by staked pivot pin  204 ) and is pivotable between a closed or lockout position ( FIGS. 6-9 ) blocking access to the bolt head  244  to prevent adjustment of the bolt  240  and an open position ( FIGS. 4 and 5 ) permitting adjustment of the bolt  240  for removal of the lockout device  200  from the toggle switch  15 . As shown, the body  210  includes an apertured tab or hasp  218  that is received through a slot  258  in the lockout cover  250  when the lockout cover is in the closed position, such that insertion of a padlock shackle (not shown) or other obstruction through the apertured tab  218  prevents movement of the lockout cover to the open position. Other lockout arrangements may additionally or alternatively be utilized. For example (not shown), a lockout device may include a lockout aperture positioned proximate to the adjustable bolt head (or other adjusting arrangement), such that insertion of a padlock shackle through the lockout aperture directly blocks access to and/or adjustment of the adjusting arrangement. As another example, a locking feature (e.g., padlock, locking bolt) may be secured with the adjusting bolt (or other adjusting mechanism) to secure the adjusting mechanism against movement. 
     As shown in  FIGS. 6 and 7 , to prevent movement of the toggle switch  15  of a first switch assembly  10  to the actuating position A, the bottom surface  211  of the body  210  includes a stop portion or fixed cleat, shown in the exemplary embodiment as a protrusion  213 , that extends past the outer surface  14  of the switch base  11  to provide a positive stop engagement with an end wall  13  of a switch assembly  10  to limit movement of the toggle switch. When the switch lockout device  200  is secured to the toggle switch  15  of the first switch assembly  10 , the protrusion  213  engages the end wall  13  of the switch assembly  10  to block movement of the toggle switch  15  to the actuating position. As shown, the toggle switch  15  with the assembled lockout device  200  has a limited range of movement between the limit position and engagement of the protrusion  213  with the end wall  13 , while still preventing movement of the toggle switch to the actuating position A. As shown, the protrusion  213  may be contoured to be wedged between the end wall  13  and a recessed extended surface  19  of the toggle switch  15 . 
     To prevent movement of the toggle switch  15   a  of a dimensionally different (e.g., extended toggle switch stroke) second switch assembly  10   a  to the actuating position A, for which the protrusion  213  does not adequately limit toggle switch stroke (as evident in  FIG. 8 ), the switch lockout device  200  includes an adjustable stop or cleat  260  that is movable from a retracted position ( FIGS. 6-8 ) to an extended position ( FIG. 9 ) to extend from the bottom surface  211  of the lockout device body  210  to provide an alternative stop position corresponding to the toggle switch stroke of the second switch assembly  10   a . In the illustrated example, the adjustable cleat  260  is hingedly connected to rear flange portions  219   a ,  219   b  of the body  210  (e.g., by a staked pivot pin  205 ), for pivoting movement of the cleat  260  between the retracted and extended positions. The adjustable cleat  260  may include a rib  263  or other such feature to facilitate user grasping for pivoting movement of the cleat between retracted and extended positions. In the illustrated embodiment, the lockout cover  250  includes an edge portion  254  that engages the extended cleat  260  when the cover is in the closed position, thereby securing the cleat against retraction. This edge portion  254  may also secure the retracted cleat in the retracted position when the cover is closed. In other embodiments (not shown), other movable cleat arrangements may be employed, such as, for example, sliding, ratcheting, or threadably adjusted stop portions. 
     When the switch lockout device  200  is secured to the toggle switch  15   a  of the second switch assembly  10   a , the extended cleat  260  engages the end wall  13   a  of the switch assembly  10   a  to block movement of the toggle switch  15   a  to the actuating position. As shown, the toggle switch  15   a  with the assembled lockout device  200  has a limited range of movement between the limit position and engagement of the protrusion  213  with the end wall  13   a , while still preventing movement of the toggle switch to the actuating position A. 
     When the switch lockout device  200  is assembled with the first switch assembly  10 , for which the protrusion  213  engages the switch end wall  13  to prevent actuation, as shown in  FIG. 7 , the adjustable cleat  260  may be maintained in a retracted position, for example, to prevent interference with installation of the lockout device  200  on the switch assembly  10 . 
     In the illustrated embodiment, the adjustable cleat  260  includes first and second switch engaging portions  261   a ,  261   b  separated by a cutout portion  262  ( FIG. 4 ) positioned to accommodate the bolt  240  when the adjustable cleat  260  is in the retracted position. 
     Still other switch lockout arrangements may be utilized in accordance with other aspects of the present disclosure. For example, as schematically shown in  FIG. 10 , a lockout device  300  may include multiple adjustable cleats  360   a ,  360   b  (e.g., similar to the pivotable adjustable cleat  260  of the embodiment of  FIGS. 4-9 ), in addition to or in place of a fixed cleat or stop protrusion, positioned along the length of the body  310  to provide a stop feature at a selected one of a plurality of positions for installation with a variety of dimensionally different switch assemblies. As another example, as shown in  FIG. 11 , a lockout device  400  may include a longitudinally adjustable cleat  460 , in addition to or in place of a fixed cleat or stop protrusion, positionable along the length of the body  410  to provide a stop feature at a selected one of a plurality of positions for installation with a variety of dimensionally different switch assemblies. Longitudinal adjustment of the cleat  460  may be provided using a variety of mechanisms, including, for example, one or more of a sliding mechanism, a ratcheting mechanism, and a threaded mechanism. 
     While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions—such as alternative materials, structures, configurations, methods, circuits, devices and components, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure, however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Parameters identified as “approximate” or “about” a specified value are intended to include both the specified value and values within 10% of the specified value, unless expressly stated otherwise. Further, it is to be understood that the drawings accompanying the present disclosure may, but need not, be to scale, and therefore may be understood as teaching various ratios and proportions evident in the drawings, either as explicitly shown, or as an approximation (i.e., +/−10%). Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention, the inventions instead being set forth in the appended claims. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated.