Abstract:
A cable actuated emergency stop system is disclosed, which includes a housing structure within which a single shaft assembly can be maintained for engaging a cable and a single shaft assembly that can be attached to the cable, wherein the single shaft assembly comprises only one shaft that is slideably disposed within the housing structure and movable relative to the housing structure a long a single path in a direction parallel to an axial centerline of the shaft in response to a force exerted by the cable attached to at least one end of the shaft. The system is configured in the context of a single directional cable actuated emergency stop device which includes one operating shaft exiting the housing structure.

Description:
TECHNICAL FIELD  
       [0001]     Embodiments are generally related to cable actuated devices. Embodiments are specifically related to directional cable actuated emergency devices usable with manufacturing equipment and the like, and additionally for improving the safety of manufacturing operating equipment.  
       BACKGROUND OF THE INVENTION  
       [0002]     Many types of cable actuated switches are known to those skilled in the art. Cable actuated switches are typically used in applications where an emergency stop capability is required along an extended distance, such as assembly lines. Manufacturers, for example, typically use cable pull safety devices as a low-cost emergency stop device for long conveyor lines or large machines. In certain conveyor system applications it is often necessary to provide a means for operators to actuate the emergency stop condition from many different locations along the conveyor.  
         [0003]     Cable activated switches that have been provided generally include a switch support body that has a bore there through. A first switch contact member is generally retained on the body and a second switch contact member is further slidingly retained on the body and insulated therefrom. Clamping means are typically provided for securing the cable passing through the bore. First resilient mechanisms are also provided to bias electrical or manual contact members. During operation, or reaction to a safety hazard, first and second contact members are displaced relative to each other by predetermined axial movement of the cable that passes through the support body. The result is generally the emergency termination of industrial or manufacturing mechanical processes.  
         [0004]     Cable controlled electrical safety switch devices have also been provided that include a piston tensioning cable under the action of a spring via a rod and a screw thread for adjusting the tension of the spring and of the cable. A piston groove actuates a push member for the switch. The piston can be angularly adjustable. When the cable is long, a high tension is selected so the groove flank moves away from the push member. Distancing is desirable in such systems in order that any length variations due to heat, which are greater with a long cable, may be prevented from triggering the switch. The clearance between the other flank and the push member is then corrected by rotation of the piston.  
         [0005]     Because electrical switches for preventing an accident in a mechanism employing a control cable can generally be included in a casing having a pair of contacts at opposite inner side surfaces thereof and an insulator member having a movable contact, an insulation member may be configured such that it is slideably and axially moved within the casing in connection with tensile force of inner cables. When the inner cables become inoperable because of some problem, the movable contact is touched to the contacts provided on the inner side surfaces of the casing in order to detect the problem or to stop the movement of the mechanism.  
         [0006]     U.S. Pat. No. 5,665,947, which issued to Falcon on Sep. 9, 1997, and is owned by the assignee of the present invention, describes a cable switch actuating mechanism, which is provided with a shaft, and a cam structure that slides on the shaft. When the associated cable is pulled to exert an axial force on the shaft, the cam actuator is pushed by the shaft into a deactuating position that moves a switch operator plunger against a plunger of an associated electrical switch. If the cable breaks, the reduction of force on the shaft allows an internal spring to move the shaft against the cam structure and, as a result, move the switch operator into its deactuating position. Appropriate gaps between the opposite ends of the cam structure and associated surfaces of the shaft were provided by design to allow for thermal expansion and contraction of the cable without adverse affects on the mechanism.  
         [0007]     U.S. Pat. No. 5,821,488, which issued Oct. 13, 1998, is an improvement over the cable operated switching mechanism described in the &#39;947 patent described above and is also assigned to the assignee of record for the present invention. The improvement is the provision of a latch device associated with a reset plunger which is movable between a normal operating position and a resetting position, wherein the cam structure is moved by the reset plunger to unlock the switch operator when the reset plunger is moved to the resetting position. The positive locking method of the cable operated switching mechanism latches a cam structure in place after the cable is pulled by an operator and does not permit the cam structure to return to its normal operating position until manual intervention is used to push a reset plunger. The cable operated switching mechanism provided a positive stop by incorporating a tab on a latching device, which is associated with the reset plunger and moves with it when a reset button is pushed.  
         [0008]     The tab of the latching device slides along a first surface of the cam structure until the cable is pulled to activate the mechanism. Then, under the influence of a spring, the latching device moves upward to cause the tab to move into a blocking position relative to a second surface of the cam structure. The tab prevents the cam structure from moving from its actuated position to its normal operating position until a reset button is pushed. This mechanism overcomes a possible problem wherein a loosely assembled cable, with too much slack, could otherwise allow a switch to be activated by the mechanism, following deactivation by an operator pulling the cable.  
         [0009]     U.S. Pat. No. 6,501,040, which issued on Dec. 31, 2003 and is owned by the assignee of the present invention describes a dual directional cable actuated emergency stop device is provided having two shaft assemblies attachable to respective cables spanning along an industrial and/or manufacturing operation. The first shaft assembly is slideably disposed within a housing structure and movable relative to the housing structure along a first path in a direction parallel to an axial centerline of the shaft in response to a force exerted by a cable attached to an end of the first shaft. The second shaft assembly is slideably disposed within the housing structure and movable relative to the housing structure along a second path in a direction parallel to an axial centerline of the shaft, and opposite movement of the first shaft, in response to a force exerted by a cable attached to an end of the first shaft.  
         [0010]     A switch operator movable along a second path between a first position and a second position is responsive to movement of the first or second shaft assemblies and is also responsive to a mechanism for locking the switch operator in a second position after the switch operator moves into a second position. At least one electrical switch associated with the device can be actuated when the switch operator is in the second position and deactuated when the switch operator is in the first position. Windows formed on the device housing cover allow a user to monitor tension of first or second cables attached to respective first and second shaft assemblies, based on the position of a cam associated with each shaft assembly.  
         [0011]     When long cable lengths are used in association with a cable actuated switch, changes in temperature can activate or deactivate the switch because of the resultant changes in the length of the cable as a result of the cable&#39;s thermal coefficient of expansion. With regard to the expansion or contraction of the cable as a result of temperature change, it is much more common for most cables to experience high temperatures during extended use than when the cable was initially installed. In some environments, opposite extreme conditions may exists (e.g., lower temperatures than experienced during initial installation). This occurs because many applications of cable-actuated switches are used in circumstances, such as warehouses, where there may be large variation in temperature that affect the cables characteristics. Furthermore, heating or air conditioning may or may not be provided for winter or summer conditions in such environments. As a result, heating systems are able to maintain the apparatus at normal operating temperatures during winter months, but no air conditioning systems are provided to maintain the apparatus at normal operating temperatures during summer months. As a result, the cables can expand beyond their normal lengths during summer months.  
         [0012]     Rather than provide numerous emergency stop switches at multiple locations along the equipment, it is sometimes deemed economically advantageous to provide a single switch that can be actuated by pulling a cable that may extend along, for example, a conveyor system from the switch to a remote location. Although the majority of cable pull devices are single direction units capable of spans up to around 200 feet, some dual directional units do exist, which in effect double the span to around 400 feet. With such long spans of cabling, malfunctions and/or false activations can be prevalent. For example, teasing of the device is found where electrical trip happens prior to mechanical trip.  
         [0013]     In a teased condition, the normally closed contacts would be open, but the normally open contacts would remain open. The normally closed contacts typically shut down the machine, and the normally open contacts typically signal (e.g., light, etc.) that the device was tripped. Therefore, if the device is teased, the machine could shut down without any indication of the source. On long conveyor lines or large machines, this situation is costly and frustrating.  
         [0014]     Another problem with such prior art devices is the difficulty associated with their set up. For example, to reset (e.g., place in run mode) a cable pull device, the cable must be set to a proper tension. Determining proper cable tension for accurate operation can be difficult. It may also be difficult to determine if the system or device is in the proper run or off state.  
         [0015]     It would be advantageous to remedy the foregoing and other deficiencies in the prior art and to facilitate the safe employment of manufacturing equipment, or the like. There is a continued need for improvement in safety mechanisms used, for example, with high-speed industrial equipment that is subject to forces that can cause an interruption in the proper operation of the equipment and can result in damage to persons and/or the equipment if the operation is not terminated in a safe manner. Accordingly, embodiments are described and presented as a novel means to address the shortcomings of the prior art.  
       BRIEF SUMMARY OF THE INVENTION  
       [0016]     The following summary of the invention is provided to facilitate an understanding of some of the innovative features unique to the present invention and is not intended to be a full description. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole.  
         [0017]     It is, therefore, one aspect of the present invention to provide for an improved cable actuated device.  
         [0018]     It is another aspect of the present invention to provide for a single directional cable actuated emergency device that can be utilized with manufacturing equipment and the like for improving the safety of operating the equipment.  
         [0019]     The aforementioned aspects of the invention and other objectives and advantages can now be achieved as described herein. A cable actuated emergency stop system is disclosed, which includes a housing structure within which a single shaft assembly can be maintained for engaging a cable and a single shaft assembly that can be attached to the cable, wherein the single shaft assembly comprises only one shaft that is slideably disposed within the housing structure and movable relative to the housing structure along a single path in a direction parallel to an axial centerline of the shaft in response to a force exerted by the cable attached to at least one end of the shaft.  
         [0020]     The system is configured in the context of a single directional cable actuated emergency stop device which includes one operating shaft exiting the housing structure. Such a device is configured in a user friendly and intuitive manner, because the device includes window on a cover of the housing structure through which a user can peer in order to determine if the actuating cable has attained the proper tension or it the cable requires tightening or loosening. Diagnostics are provided by a mechanical trip indicator, so that the user can easily and visually determine if the single directional cable actuated emergency stop device is tripped or in a “run” position.  
         [0021]     The single directional cable actuated emergency stop device described herein with respect to varying embodiments provides pulled cable and slacken/broken cable detection capabilities. The single directional cable actuated emergency stop device possesses a “snap-action” mechanism that does not allow the electrical switch mechanism to be teased (i.e., electrical trip prior to mechanical trip) in either the pulled or slacked/broken cable. The single directional cable actuated emergency stop device can latch in both the pulled or slackened/broken cable, and thereafter remains latched until a reset knob or other reset device is rotated.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.  
         [0023]      FIG. 1  illustrates a top view of a single directional cable actuated emergency stop device in accordance with a preferred embodiment of the present invention;  
         [0024]      FIG. 2  illustrates a front plan view of the single directional cable actuated emergency stop device depicted in  FIG. 1  in accordance with a preferred embodiment of the present invention;  
         [0025]      FIG. 3  illustrates an opposing side view of the directional cable actuated emergency stop device depicted in  FIG. 1  in accordance with a preferred embodiment of the present invention;  
         [0026]      FIG. 4  illustrates a perspective and exploded view of the single directional cable actuated emergency stop device depicted in FIGS.  1  to  3  in accordance with a preferred embodiment of the present invention;  
         [0027]      FIG. 5  illustrates an angular view of a removable contact bock assembly, which can be implemented in accordance with the directional cable actuated emergency stop device depicted in FIGS.  1  to  4  in accordance with a preferred embodiment of the present invention;  
         [0028]      FIG. 6  illustrates an angular perspective view of a single directional cable actuated emergency stop device depicted in FIGS.  1  to  4  in accordance with a preferred embodiment of the present invention;  
         [0029]      FIG. 7  illustrates a partial cut-away side view of the single directional cable actuated emergency stop device depicted in FIGS.  1  to  4  in accordance with a preferred embodiment of the present invention;  
         [0030]      FIG. 8  illustrates a top plan view of a single directional cable actuated emergency stop device, which can be implemented in accordance with an alternative embodiment of the present invention;  
         [0031]      FIG. 9  illustrates a side plan view of the single directional cable actuated emergency stop device depicted in  FIG. 8 , in accordance with an alternative embodiment of the present invention;  
         [0032]      FIG. 10  illustrates a side plan view of the single directional cable actuated emergency stop device depicted in  FIGS. 8 and 10 , in accordance with an alternative embodiment of the present invention;  
         [0033]      FIG. 11  illustrates an exploded perspective view of the single directional cable actuated emergency stop device depicted in FIGS.  9  to  11 , in accordance with an alternative embodiment of the present invention;  
         [0034]      FIG. 12  illustrates an environment wherein a directional cable actuated emergency stop device can be utilized; and  
         [0035]      FIG. 13  illustrates an environment wherein a single cable device, similar to those taught in the prior art, is used.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]     The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment of the present invention and are not intended to limit the scope of the invention.  
         [0037]      FIG. 1  illustrates a top view of a single directional cable actuated emergency stop device  100  in accordance with a preferred embodiment of the present invention.  FIG. 2  illustrates a front plan view of the directional cable actuated emergency stop device  100  depicted in  FIG. 1  in accordance with a preferred embodiment of the present invention.  FIG. 3  illustrates an opposing side view of the single directional cable actuated emergency stop device  100  depicted in  FIG. 1  in accordance with a preferred embodiment of the present invention.  FIG. 4  illustrates a perspective and exploded view of the directional cable actuated emergency stop device  100  depicted in FIGS.  1  to  4  in accordance with a preferred embodiment of the present invention.  
         [0038]      FIG. 5  illustrates an angular view of a removable contact bock assembly  190 , which can be implemented in accordance with the single directional cable actuated emergency stop device  100  depicted in FIGS.  1  to  4  in accordance with a preferred embodiment of the present invention.  FIG. 6  illustrates an angular perspective view of the directional cable actuated emergency stop device  100  depicted in FIGS.  1  to  4  in accordance with a preferred embodiment of the present invention.  FIG. 7  illustrates a partial cutaway side view of the single directional cable actuated emergency stop device  100  depicted in FIGS.  1  to  4  in accordance with a preferred embodiment of the present invention. Note that in FIGS.  1  to  7 , identical or similar parts or components are generally indicated by identical reference numerals.  
         [0039]     An operating shaft  103  and a return spring  104  can be retained to a housing  101  using a threaded bushing  107 . Note that the housing  101  can be formed from as a die cast housing from a material such as zinc. Housing  101  can therefore be configured as zinc die cast housing. Housing  101  can also be formed of other materials such as a strong plastic, depending upon the design needs. A plastic cam  109  can be inserted onto the operating shaft  103  and retained by one or more retaining rings  102  and  189 . The plastic cam  109  can be fixed to an end of the shaft(s) (e.g., shaft  103 ) and restrained from rotating by either the housing  101  or an internal cover  124  and a spacer  109   b , which is actually another plastic cam. Therefore, the operating shaft  103  can rotate without affecting the cam  109 .  
         [0040]     A section of the cam  109  can be visible through a lens  132  in the cover  130  to provide a tensioning indication. Lens  132  generally is located by a flexible nameplate  134  configured on cover  130 . One or more screws such as, for example, screw  131 , can retain the cover  130  to housing  101 . A seal gasket  129  is located between cover  130  and housing  101 . Located between the cover  124  and cover  130  is a seal ring  127 . Screws  128  retain the cover  124  to the housing  101 . Switches  114 ,  113  can be are retained by screw(s)  115 . Device  100  also includes a seal  123  between the cam  122  and cover  124 . A bracket  111  also couples with housing  101 . Bracket  111  is connected with housing  101  via screw(s)  112 .  
         [0041]     A Pipe fitting plug  143  can be installed into unused conduit holes on housing  101 . Note that return spring  104  is located generally between retaining ring  102  and flat washer  105 , which in turn engages a seal ring  106 . Seal ring  106  contacts shouldered bushing  107  and the actuating rod and operating shaft  103 . Eye nut  108  can be attached to the operating shaft  103  as a means for attaching the actuating cable. A general bushing  138  can also engage housing  101 .  
         [0042]     The return spring  104  generally applies a force to the cam  109  and shaft  103 , thereby forcing cam  109  and shaft  103  towards the center of device  100 . If the actuating cable becomes loose, the return spring  104  applies a force to the cam  109  moving the cam position, which can be viewed through the cover  130 , indicating that the actuating cable requires adjustment. If the actuating cable is too tight (i.e., during set up or due to temperature variations), the cam position, which can be viewed through cover  130 , moves thereby indicating that the actuating cable requires adjustment.  
         [0043]     The cam profile actuates a plunger  118  that in turn can operate basic switches  113  and  114 . A “snap action” can be obtained through the implementation of a single plunger mechanism  181 , which is generally configured as an over-center type of mechanism comprising a plunger  118 , a carrier  117 , and a set of compression springs  121  and  161  respectively assembled to pivot shafts  119  and  120  and  169  and  170 . Pivot shafts  119  and  120  and pivot shafts  169  and  170  are respectively located at ends of springs  161  and  121 . An end of such pivot shafts pivots on plunger  118 . The opposite ends of the pivot shafts pivot on the carrier  117 . The plunger mechanism  181  sits within a gap or pocket within housing  101  and is retained by the internal cover  124 .  
         [0044]     Plunger  118  can be configured to include a pin  116  that allows a fork-shaped cam  122  to be attached to a reset knob  125  on the cover  124  in order to reset the cam  122 . Reset knob  125  also can function as mechanical indication of a “trip”. When the plunger  118  is “up”, the rest knob  125  is in a position that indicates “run” by pointing to the word “RUN” on cover label  133  on cover  130 . When the plunger  118  is “down”, the rest knob  125  can be rotated to a position that indicates a “trip” by pointing to the word “OFF” on the cover label  133  on cover  130 . The reset knob  125  is attached to the internal cover  124  subassembly that remains attached to of the housing  101 , so that the cover  130  is assembled to housing  101  without lining up any other components.  
         [0045]     When the operating shaft  103  is at a proper tension, the plunger  118  can be moved into a “run” position by rotating the reset knob  125 . The plunger  118  can be maintained in the “run” position by the pivot springs  161  and  121  in association with respective pivot shafts  169 ,  170  and  119 ,  120 . When the operating shaft  103  is pulled or pushed into the broken cable, the cam  109  moves the plunger  118  downward. As cam  109  and plunger  118  moves, the pivot points of the pivot springs  121  and  161  on the plunger  118  also move. After the pivot point of plunger  118  passes the pivot point on the carrier  117 , the resulting spring force pushes the carrier  117  upward and plunger  118  downward, independent of shaft movement thereof. Plunger  118  actuates the switches  113  and  114 . The use of the carrier  117  improves “snap-over” by ensuring that the springs  121  and  161  are always at an angle thereby producing vertical forces at the plunger  118 . The plunger  118  can thus be maintained in this final position by the two pivot springs  121  and  161 .  
         [0046]     Note that in  FIG. 5 , a removable contact block  190  is depicted, including a plurality of screws,  172 , and  135  thereof that can engage a plastic bracket  136  to the housing  101 . Switches  113  and  114  are also shown in  FIG. 5 , in addition to thread forming screws  115  and  195 . Nut  108  is also shown in  FIG. 6 , in addition to various views of  FIGS. 1-5 . Housing  101  is co-located with nut  108 . Note that in a single directional implementation as indicated herein, only one such nut is required. The removable contact block  190  depicted in  FIG. 5  is also shown in  FIG. 6  prior to assembly with housing  101 .  
         [0047]     As indicated in  FIG. 7 , nut  108  can be located generally at the “right” actuator portion of device  100 . In an alternative embodiment, nut  108  can be located at the left actuator portion of device  100 . The placement of nut  108  is simply a design choice. Nut  108  is also indicated in more detail  FIGS. 1, 2 , and  3 . Bushing  138  is shown in  FIG. 7  generally located at the “left” actuator portion of device  100 . In an alternative embodiment, bushing  138  can be located at the right actuator portion of device  100 . Again, the placement of features such as bushing  138  is a design preference.  
         [0048]     For a single direction right implementation, shaft  103 , spring  104 , washer  105 , seal  106 , bushing  107 , cam  109 , and nut  108  can be installed to the right of bushing  138 . For single directional left implementation, shaft  103 , spring  104 , washer  105 , seal  106 , bushing  107 , cam  109 , and nut  108  can be installed at the left and bushing  138  and cam  109  (i.e., used as a spacer) can be installed on the right. A pilot light  137  is also depicted generally in FIGS.  1  to  4 .  
         [0049]      FIG. 8  illustrates a front plan view of a single directional cable actuated emergency stop device  200 , which can be implemented in accordance with an alternative embodiment of the present invention.  FIG. 9  illustrates a side plan view of the single directional cable actuated emergency stop device  200  depicted in  FIG. 8 , in accordance with an alternative embodiment of the present invention.  FIG. 10  illustrates a side plan view of the single directional cable actuated emergency stop device  200  depicted in  FIGS. 8 and 9 , in accordance with an alternative embodiment of the present invention.  FIG. 11  illustrates an exploded perspective view of the single directional cable actuated emergency stop device  200  depicted in FIGS.  8  to  10 , in accordance with an alternative embodiment of the present invention. Note that in FIGS.  8  to  11 , identical or similar parts are indicated by identical reference numerals.  
         [0050]     An operating shaft  203  (i.e., an actuating rod or actuator) and a return spring  204  can be retained to a zinc die cast housing  201  utilizing a threaded shouldered bushing  207 . Retaining rings  202   a  and  202   b  can be utilized to assist in maintaining operating shaft  203 . A flat washer  205  is located between spring  204  and a seal ring  206 . Seal ring  206  in turn is located between the flat washer  205  and the shouldered bushing  207 . A nut  208  is thereafter connected to the operating shaft  203 .  
         [0051]     A metal plunger  214  can be inserted onto the operating shaft  203  and retaining by retaining ring  202 . The metal plunger  214  is generally fixed to the end of the shafts and is restrained from rotation by housing  201  and an internal cover  225 . Therefore, the operating shaft  203  can rotate without affecting the plunger  214 . The metal plunger  214  generally contacts the pin  277  to rotate a cam  291  that rotates about a shaft pin  213 . A label  215  on the metal plunger  214  is visible through a lens  232  in the cover  230  to provide a tensioning indication. Cover  230  can be formed from metal or plastic depending upon design needs and restraints. The return spring  204  applies a force to the operating shaft  203  and the metal plunger  214 , thereby rotating the cam  291  clockwise.  
         [0052]     If the actuating cable becomes loose, the return spring  204  applies a force to operating shaft  203 , moving the metal plunger  214 , which can be viewed through cover  230 , indicating that the actuating cable requires adjustment. If the actuating cable or operating shaft  203  is too tight, the metal plunger  214  position, which can be viewed through cover  230 , moves, indicating that the actuating cable or operating shaft  203  requires adjustment.  
         [0053]     The cam profile actuates a plastic plunger  219  that in turn operates the basic switches  210  and  211 . The “snap action” is obtained by a single plunger mechanism  308 , which functions as snap-action and over-center type of mechanism. Plunger mechanism  308  generally includes a plunger  219 , a carrier  218  and set of compression springs  221  and  281  which are respectively assembled to pivot shafts  220 ,  222  and  280 ,  282 . One end of the pivot shafts pivot on the plunger, while the opposite end of the pivot shafts can pivot on the carrier  218 . The plunger mechanism  308  can sit within a pocked or cavity formed from and surrounded by housing  201  and also retained by internal cover  225 .  
         [0054]     Plastic plunger  219  can also include a pin  217  that allows a fork-shaped cam  223  to be attached to a rest knob  227  on the cover  225  to reset the plunger mechanism  308 . The reset knob  227  can also function as a mechanical indication of a “trip”. When the plastic plunger  219  is “up”, the reset knob  227  is in a position that indicates “run” by pointing to the word “RUN” on the cover label  234 . When the plastic plunger  219  is “down”, the reset knob  227  can be rotated to a position that indicates a “trip” by pointing to the word “OFF” on the cover label  234 . The reset knob  227  is generally located on a subassembly of housing  201 , so that the cover  230  can be easily assembled to housing  201  without aligning other components.  
         [0055]     A cable (not shown in  FIGS. 8-11 ) can be attached to operating shaft  203  via nut  208 . The cable can be tightened until the label  215  on the metal plunger  214  is centered on the cover lens  232 . Note that a seal  231  is located between lens  232  and cover  230 . One or more screws  233  can be utilized to maintain cover  230  to housing  201 . Additionally, a seal ring  238  can be connected to a light pipe  237  at plate or cover  230 . A flexible nameplate  235  and nameplate  234  can be assembled to the sheet metal cover  230 . Note that cover  230  can be formed from material other than sheet metal, such as plastic.  
         [0056]     Cover  230  is located next to a gasket seal  229 . A push-on nut  239  is assembled to the light pipe  237 . A screw  228  connects the reset knob  227  to the cam  223 . Thread cutting screws  226  can be utilized to assemble the cover  225  to the housing  201 . A seal ring  224  also engages cover  225  at cam  223 . The cam  291  rotates about pin  213 . Pin  213  is retained by the housing  201  and cover  225 . A label  301  can also be incorporated on or into housing  201  to provide information about parts within housing  201 . An additional pin  277  can be inserted through cam  291 . A retaining ring  202   a  and  202   b  connects the plunger  214  to the shaft  203 . A pilot light  240  can also be assembled into housing  201 . An assembled washer screw  209  can be connected to the housing  201  for the end user to make an electrical termination to earth ground. Screws  212  retain switches  211 ,  210 . A fitting  241  also connects to housing  201 .  
         [0057]     At proper tension, the plastic plunger  219  can be moved into the “run” position by rotating the reset knob  227 . The plastic plunger can be maintained in the “run” position by the pivot springs  221  and  281 . When the shaft  203  is pulled or pushed into the broken cable, the metal plunger  214  rotates that cam  291 , which moves the plastic plunger  219  down. As the cam  291  and plastic plunger  219  moves, the pivot point of the pivot springs on the plunger  219  moves.  
         [0058]     After the pivot point of the plastic plunger  219  passes the pivot point on the carrier  218 , the spring force pushes the carrier  218  “up” and the plastic plunger  219  “down” independent of the movement of shaft  203 . The plastic plunger  219  can then actuate the switches  210 ,  211 . The use of the carrier  218  improves “snap over” by ensuring that the springs  221  and  281  are always at positioned at an angle, thereby producing vertical forces at the plastic plunger  219 . The plastic plunger  219  is maintained in the final position by the two pivot springs  221  and  281 . The two plungers  214  and  219  do not have to be metal and plastic, but can be configured using other materials.  
         [0059]     Referring to  FIG. 12 , an illustrated example is provided of a manufacturing environment wherein the device described herein s can be implemented. The configuration of  FIG. 12  depicts a conveyor system  1301  which can be utilized in an assembly line. Although system  1301  is labeled as “prior art” in  FIG. 12 , but it can be appreciated that system  1301  can be modified and adapted for use with one or more embodiments of the present invention. The device  1305  can be secured in its placement between a cable  1302 . The cable  1302  is generally within the reach of the operator  1310  so that an emergency may be indicated by the manual placement of tension on the cables. Tension can occur purposely where the operator had manually placed pressure on the cable or where the operator had become placed dangerously into interference with the conveyance system.  
         [0060]     The benefit of using a single directional cable actuated emergency device as described herein with respect to embodiments is apparent given the present teachings and illustration, especially for lengthy industrial application such as the illustrated conveyor line  1301  of  FIG. 12 . For example, the span of cable indicated by reference  1306  in  FIG. 12  can easily meet all manufacturing and industrial requirements with spans reaching 100 ft or more. It should also be appreciated given the teachings herein, that other members extending from the device may be used to interrupt operation. For example, string, rope, wire, threaded screws or fasteners, elongated members such as poles (plastic, metal, wood), or a combination of any of the above materials including mesh or net material. These materials are known to be accessible to operators at production sites and can be used to interfere with operations when actuated by physical disturbance by personnel. Therefore, the term “cable” is broadly defined herein as including all of the aforementioned examples.  
         [0061]     Referring to  FIG. 13 , an example illustration of the same environment is shown wherein only a single action device  1405 , as currently provided in the art, is utilized.  
         [0062]     The embodiment and examples set forth herein are presented to best explain the present invention and its practical application and to thereby enable those skilled in the art to make and utilize the invention. Those skilled in the art, however, will recognize that the foregoing description and examples have been presented for the purpose of illustration and example only. Other variations and modifications of the present invention will be apparent to those of skill in the art, and it is the intent of the appended claims that such variations and modifications be covered.  
         [0063]     The description as set forth is not intended to be exhaustive or to limit the scope of the invention. Many modifications and variations are possible in light of the above teaching without departing from the spirit and scope of the following claims. It is contemplated that the use of the present invention can involve components having different characteristics. It is intended that the scope of the present invention be defined by the claims appended hereto, giving full cognizance to equivalents in all respects.  
         [0064]     The embodiments of the invention in which an exclusive property or right is claimed are defined as follows. Having thus described the invention