Abstract:
A pull station for an alarm includes a housing with a handle mounted for sliding movement within the housing. The housing includes a window for a user to access the handle for forcibly sliding the handle in a vertical direction. A latch is rotatably mounted to the handle and spring biased to rotate to a locked position upon sliding movement of the handle. The latch has a portion which moves to bear against a stationary element of the housing to establish the locked position. The housing can be opened to reset the handle without changing the state of the alarm. Closing of the housing automatically resets the alarm. An attached terminal block includes a plurality of U-shaped terminal elements each having a screw terminal, a solder lug and a press pin.

Description:
This application is a divisional application of U.S. Ser. No. 09/373,867 filed Aug. 13, 1999, now U.S. Pat. No. 6,380,846. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to emergency pull stations, such as pull stations for triggering fire alarms. 
     BACKGROUND OF THE INVENTION 
     In known fire alarm pull stations, a lever is provided which can be manually pivoted or depressed to set off a local or centralized fire alarm. Such fire alarms are typically present in buildings such as schools, hospitals, and the like. The alarm pull stations mount on a wall and are typically color coded to be easily recognizable in an emergency. 
     Such pull stations are manufactured for example by Pittway Corporation, NOTIFIER Division, such as models: NBG-10 series Non-Coded Manual Fire Alarm Station, BGX-101L Addressable Manual Pull Station, BNG and BRG series Manual Fire Alarm Stations or LNG Double-Action Manual Fire Alarm Station. 
     To prevent vandalism or nuisance alarms involving such pull stations, the pull stations are configured to lock in the alarm state once the activation lever is depressed or otherwise placed in an alarm state. To reset a pull station, a key is required to release the lever to its initial, non-alarm state. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the invention, a pull station for an alarm system includes features adapted to enhance manufacturing, assembly and effectiveness of the pull station. The pull station includes a back plate or base plate which carries an alarm switch on a front side and a terminal block on a back side. 
     A cover is hingedly connected to the back plate. The cover carries a handle slidably held thereto that is accessible through an opening in a front wall of the cover. The handle is biased upwardly and when forcibly pulled downwardly, activates the alarm switch. 
     A latch is carried by the handle. The latch moves with the handle and engages an abutment of the back plate to prevent upward retraction of the handle, when the handle has reached its downward, alarm position. 
     A lock is mounted in an opening in the front wall of the cover. When locked, the lock fixes the cover to the back wall in a closed configuration. Once the handle is pulled to its alarm position, the lock must be unlocked, the cover opened and the latch disengaged from the abutment to retract the handle to reset the pull station. 
     The handle includes a body portion having a switch activator facing rearwardly thereof. The switch activator includes a structure which captures a switch lever of the alarm switch such that sliding movement of the body portion changes the state of the alarm switch. Additionally, a contoured ramp of the structure acts to reset the switch lever when the cover is pivotally closed to the back plate. 
     The body portion includes outwardly extending tabs on a top end thereof, on opposite lateral sides of the body portion, which are slidably captured in side channels of the cover. The handle also includes an extension portion connected to, such as being formed with, a lower end of the body portion. The extension portion includes a front wall portion having an elongated slot, elongated in a direction of sliding movement of the body portion. 
     According to different fire codes, pull stations must have handles which operate in either a single action, such as a “pull down”, mode or in a double action, such as a “press in and then pull down”, mode. In a first, single action, configuration, an anchor portion having an outwardly directed stop portion is connected to a rear side of the cover front wall, the anchor portion having a circular base portion that penetrates the elongated slot. The stop portion overlies the front wall portion of the extension portion on lateral sides of the slot to capture the extension portion onto the cover front wall but which allows sliding of the extension portion with respect thereto. 
     In an alternate double action configuration, the anchor portion is mounted with the stop portion located between the extension portion and the front wall of the cover. The stop portion fits into stop grooves formed on the front side of the extension portion. In this orientation, the stop portion serves as a blocking member which abuts side walls of the stop grooves on a front surface of the extension portion and prohibits the handle from sliding downwardly unless the handle is first pushed in and then slid downwardly. 
     When pushed in, the stop portion clears the stop grooves and the handle can be slid downwardly. The spring loaded latch provides a resilient opposition or “feel” to pushing in the handle. 
     The extension portion includes substantially parallel side walls, extending from the extension portion front wall rearwardly. The latch is rotatably mounted between, and to, the side walls. A torsional spring biases the latch to rotate toward an engagement position, with a latch tip of the latch pressed against the back plate. 
     The back plate includes a stepped surface extending forwardly thereof and in registration with the latch. The stepped surface includes a forward surface parallel to a back surface of the front wall of the cover and arranged at a first distance from the back surface of the front wall of the cover, to be pressed by the latch tip. The stepped surface has a rearward surface parallel to the back surface of the front wall of the cover and arranged at a second distance from the back surface of the front wall of the cover, the second distance greater than the first distance. A perpendicular surface is formed between the forward and rearward surfaces. 
     During sliding of the handle with respect to the cover and back plate, the latch tip slides on the forward surface and, under force from the torsional spring, moves between the forward and rearward surfaces. In this position, an end of the latch, that is adjacent to the latch tip, can abut the perpendicular surface. The perpendicular surface, by abutment against the latch end, prohibits the latch element from proceeding in a reverse direction, which in turn prohibits the handle from being slid in a reverse direction. 
     In order to reset the handle to its elevated position, the cover must be unlocked and opened. When the cover is opened, the latch will disengage the stepped wall and the handle will be automatically retracted upwardly by the spring. When the cover is subsequently closed against the base plate, the latch will be forced to resiliently rotate to assume its position pressed against the forward surface of the stepped wall. 
     The exemplary embodiments of the invention reduce or eliminate fasteners in the assembly and include the ability to assemble the components in two configurations for two operating modes: a handle slide down only mode, and a handle press inwardly and then slide down mode. The pull station can be configured and assembled in either configuration without requiring different parts or fasteners. The cover is connected to the base plate without use of fasteners. The spring loaded latch is also snap fit to the handle, without requiring fasteners. 
     The handle is assembled to the cover without fasteners. In the first configuration, the handle is slid onto the cover at a top end of the handle, with the handle at about 90° to the cover, and then the handle is pivoted toward the cover 90° and secured by the anchor member with the stop portion overlying the extension portion. The handle is thus attached for sliding movement with respect to the back plate. 
     In the alternate configuration, the handle is slid onto the cover at the top end of the handle with the handle at 90° to the cover. The anchor member is comparatively oriented turned over and rotated 180° compared to the first configuration. The anchor member is attached to the cover. The handle is then pivoted toward the cover by about 90°. 
     The extension portion is guided by the anchor member for sliding movement, but not restrained against the cover, by the anchor member. The extension portion is urged toward the cover by the resilient pressing of the latch against the back plate. 
     The electric terminals which are mounted to a back of the pull station, are configured to be pressed in place using barbed legs of a U-shaped body. The terminals are set at a standard 0.375 inch spacing and each provides a solder lug, a screw terminal and a pin connector. The screw terminal is configured to accept a two wire lead. The U-shaped body provides an interior region or space for the threaded shaft of the screw terminal to enter. 
     According to another aspect of the invention, the handle can be composed of transparent or translucent material, such as plastic material. The switch module can include an LED status annunciator located behind the handle. A blinking of the LED for example can indicate a “ready” condition of the pull station. 
     According to another aspect of the invention, a PC board inside the housing can be mounted according to two orientations, to avoid covering the housing mounting holes for mounting the housing to an electrical box or other mounting structure or surface. 
     Also, the cover of the module includes the warning message, such as the word “FIRE”, molded as a recess into the cover and the word is hot stamped in white within the recess. 
    
    
     Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings in which details of the invention are fully and completely disclosed as part of this specification. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an assembled pull station of the present invention; 
     FIG. 2 is a perspective view of the pull station of FIG. 1 with a cover open with respect to a base plate; 
     FIG. 3 is an elevational view of the pull station of FIG. 2 with the cover completely opened; 
     FIG. 4 is an elevational view of the pull station of FIG. 3 with the cover disengaged from the baseplate; 
     FIG. 5 is a perspective new of the handle partially engaged into the cover; 
     FIG. 6 is a side view of the initial engagement and rotation into position of the handle with regard to the cover; 
     FIGS. 7A and 7B illustrate the interaction between the cover, the handle and the latch mechanism of a dual action, press in and slide down mode of handle operation, progressively as the handle is moved into its alarm state; 
     FIGS. 7C and 7D illustrate the interaction between the cover, the handle and the latch mechanism of a single action, slide down only mode of handle operation, progressively as the handle is moved into its alarm state; 
     FIG. 8 is an enlarged fragmentary plan view of the cover of FIG. 4 illustrating a dual action configuration of the handle, anchor, and cover; 
     FIG. 9 is a fragmentary plan view of a modified cover illustrating a single action configuration of the anchor, handle, and cover; 
     FIG. 9A is a fragmentary sectional view taken generally along line  9 A— 9 A of FIG. 9; 
     FIG. 10 is an enlarged fragmentary perspective view of the cover of FIG. 8 or  9 ; 
     FIG. 11 is a rear-view of the baseplate shown in FIG. 4; 
     FIG. 12 is a top plan view of the baseplate shown in FIG. 11; 
     FIG. 13 is a cross sectional view taken generally along line  13 — 13  of FIG. 10; 
     FIG. 14 is a perspective view of a monitor module taken from FIG. 13; 
     FIG. 15 is an exploded perspective view of the monitor module of FIG. 14; 
     FIG. 16 is an enlarged perspective view of one contact assembly taken from FIG. 13; and 
     FIG. 17 is a fragmentary, enlarged plan view of a portion of the contact assembly shown in FIG.  16 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
     FIG. 1 illustrates a pull station  100  having a baseplate  106 , and a cover  108  which together form a housing  109 . The pull station  100  includes a handle  110  arranged between the base plate  106  and the cover  108 . 
     The cover  108  is hinged to the base plate by a releaseable hinge assembly  111  (shown in FIGS. 3 and 4) which includes upper and lower hinge pins  112 ,  114  respectively on the baseplate  100  and corresponding sockets  116 ,  118  on the cover. The cover  108  includes a front wall  119  having a window  120  which exposes a recessed gripping portion  122  of the handle to allow manual movement of the handle within the housing  109 . 
     A lock cylinder  126  is carried by the front wall  119 , exposed through an aperture  128  through the front wall  119 . The lock cylinder includes a keyhole  130  for receiving a key or a tool to lock or unlock the free edge of the hinged cover  108  to/from the base plate  106 . 
     For a fire pill station, the housing is usually red in color. The front wall  119  includes the lettering “FIRE” for example. The lettering is formed by hot stamping white letters  129  within wider, correspondingly shaped recesses  131 , forming letter shaped grooves  133  into the front wall  119 . The white letters  129  set into the red cover  119  are visually distinctive. Also, due to the presence of the grooves  133 , even if the front wall  119  and the letters  129  are over-painted the same color, the letters as defined by the grooves  133 , will still be visually perceptible. Preferably the grooves  133  have a significant aspect ratio (depth to width ratio) to prevent the obliteration of the lettering due to such an over-painting. The letters  129  have a front surface which is flush with the surrounding front surface  121  of the wall  119 . Thus, if desired, a label can be smoothly applied over the letters  129  to apply a different message, such as a message in a foreign language. 
     FIG. 2 illustrates the housing  109  in an open configuration. The handle  110  includes a body portion  132  which is biased by a spring  134  to an elevated position on the cover  108 . The spring  134  is connected to a hoop portion  136  on the cover  108  and to a hook portion  135  on the handle  110 . For purposes of description, the spring is shown disconnected from the hook portion. 
     The handle  110  also includes a relatively narrow extension portion  138  connected to the body portion  132 . The lock cylinder  126  includes an output shaft  140  which is connected to rotate a lock cam  142  upon turning of the key from a front side of the cover  108 . 
     The extension portion  138  includes a front wall portion  144  having an elongated slot  148 . The slot  148  is elongated in a vertical direction, i.e., the direction of movement of the handle  110 . 
     The extension portion  138  further includes parallel side walls  150 ,  152  extending from the front wall portion  144  in a substantially perpendicular direction. A latch mechanism  160  is located between the side walls  150 ,  152  and is carried for rotation at each side wall  150 ,  152 . 
     As illustrated in FIGS. 2 and 10, the latch mechanism or “trigger”, includes two sidewall portions  162   a ,  162   b  which fit between the side walls  150 ,  152 . The side wall portions  162   a ,  162   b  carry cylindrical axle stubs  163   a ,  163   b  which extend outwardly from respective side wall portions  162   a ,  162   b  and are journalled for rotation into round sockets or holes  165   a ,  165   b  formed into the respective side wall  150 ,  152 . 
     The side wall portions  162   a ,  162   b  carry therebetween a latch element  164  at an upper end and a brace bar  165  at a lower end. A spring guide rod  166  extends horizontally from the side wall portion  162   a  toward the side wall portion  162   b . The latch element  164  includes a latch tip  167  and a latch end face  168 . A torsion spring  244  surrounds the guide rod  166  and biases the latch element toward the back plate  106 . 
     The body portion  132  also includes a switch activating wall  172  and a switch deactivating wall  174  having a ramped portion  174   a . The base plate  106  includes a covered switch element  180 . The state of switch  180  is altered, activated and deactivated, by a switch paddle or lever  184 . 
     When the cover  108  is closed to the base plate  106 , the switch lever is captured between the walls  172 ,  174 . The switch lever is moved to activate or deactivate by the walls  172 ,  174  respectively. A downward movement of the handle  110  causes switch activating wall  172  to toggle the switch paddle  184  down to an activated position, at which time the “trigger”  160  locks the handle into the downward “alarm” position (FIG. 7B or  7 D). To reset the switch  180  to “normal”, cover  108  must be opened to allow handle  132  to return to the non-activated state (FIG. 3) by force from the spring  134 . Upon closing the cover  108 , the ramped portion  174   a  (FIG. 10) slidingly engages switch paddle  184  and forces it upwardly. The handle  132  and switch  180  are now both reset to normal. 
     Switch  180  snap-fits into baseplate  106 . Opening the cover  108  does not change the state of switch  180 . Hence cover  108  can be opened for inspection and maintenance without setting off an alarm. Alternately, cover  108  could be opened and a switch  214  depressed to generate a signal, distinguishable from the alarm signal generated by switch  180 . Opening or closing the cover  108  does not change the state of the switch  214 . 
     A printed circuit board or other control circuit could be positioned within an open space  193  located upwardly of the switch  180  and mounted to one or more of the screw bosses  195  provided. A possible vertically elongated orientation is shown as  193   a  and a possible horizontally elongated orientation is shown as  193   b . A plurality of conductor pins  316  (described below) are exposed beneath the PCB locations  193   a ,  193   b . The conductor pins can be connected to contacts on a PCB board in similar fashion as described below. 
     The base plate  106  includes a back wall  196  having a variety of openings  198  for supporting the pull station  100  on an electrical box, a wall surface or other structure. A comer wall  202  is arranged to be captured by the lock cam  142  to maintain the cover  108  locked to the base plate  106 . The lock cam  142  is rotated to abut a backside surface  202   a  of the comer wall  202 . 
     FIG. 3 illustrates one configuration of the pull station with a monitor module  191 . The monitor module  191  includes a case  192  that carries address setting dials  206 ,  208  and an LED  210 . The monitor module in this configuration, provides an interface between a centralized alarm monitoring system and the pull station. The address setting dials each include for example 10 digit settings, 0 through 9, so that the dials together provide a possibility of address settings of 0 through 99. The address settings provide a unique address number to the particular pull station so that when actuated the centralized monitoring system can identify the location of the pull station compared to other pull stations on the loop of the monitoring system. A known monitoring system is model MMX-101, manufactured by the System Sensor division of Pittway Corporation. 
     For the LED  210  to be observable in operation, the handle  132  must be transparent or translucent, or the cover  108  opened. The body portion  132  of the handle  110  is preferably composed of a transparent or translucent material, such that the LED  210  can be observable from outside the closed pull station. 
     The switch  180 , when actuated, can signal a local or centralized alarm signal. Alternatively, the switch  180  can be used in conjunction with the optional rocker switch  214  to trigger a “presignal” alarm which requests an inspection of the pull station to ascertain if the actuation of the alarm is legitimate, i.e., is not a nuisance alarm. In this case, an authorized person with a key to the cover lock would open the cover to reset the handle and, if the emergency condition is legitimate, the person could at that time actuate a rocker switch  214  to cause a general alarm, either locally or at the centralized system. The rocker switch is entirely secured inside the cover so that only an authorized person can actuate the general alarm. This presignal feature is also useful for testing the operability of pull stations without actually sounding unnecessary alarms. Switch  214  can be used in different ways without departing from the spirit and scope of the present invention. Switch  214  is not activated by the movement of the handle  132 . 
     FIG. 4 illustrates the cover  108  opened with respect to the base plate  106 . The hinge sockets  116 ,  118  have been lifted out of engagement with the hinge pins  112 ,  114 . The cover  108  can then be separated from the base plate  106 . Installation is according to a reverse procedure. No fasteners are required to install the cover to the base plate. 
     As illustrated in FIG. 5, the cover  108  includes side channels  220 ,  222  formed by substantially L-shaped wall members  220   a ,  222   a  at a top end  108   a  of the cover. During assembly of the handle to the cover  108 , the handle  110  is positioned at about a 90 degree angle to the cover (as shown in FIG.  6 ). The handle  110  is then slid toward the top end  108   a  of the cover. The side channels receive laterally extending tabs  226 ,  228  therein. The handle  110  is then pivoted downwardly in the direction P toward the cover (as shown on FIG. 6) to its installed position in the cover. Once pivoted down, the handle  110  can not be pulled out of the side channels/traces  220 ,  222 . 
     An anchor member  232  is fixed to the cover  108  either before or after the handle is pivoted to the installed position, depending on the handle actuation mode. The anchor member  232  is positioned to be received in the slot  148 . 
     For a press in and slide down mode of handle operation, the anchor member  232  is attached as shown in FIG. 5 with the stop portion  256  registering with stop grooves  257 ,  258  formed on a front side of the wall portion  144  of the extension portion  138 . The engagement of the stop portion with the stop grooves prevents sliding of the handle with respect to the cover unless the handle is first depressed inwardly to disengage the stop grooves from the stop portion as described in FIGS. 7A and 7B. 
     For a slide-only mode of handle operation, the anchor member is turned upside down and rotated 180 degrees from the position shown in FIG.  5 . The anchor member is attached to the cover, through the slot  148 , after the cover is pivoted to the installed position. Once fixed into position within the slot  148 , the anchor member  232  prohibits the handle from being pivoted away from the installed position, and only allows sliding movement of the handle within the housing  109  as described in FIGS. 7C and 7D. 
     FIG. 6 illustrates the position and orientation of the tab  226  as it enters a mouth  221  of the channel  220 . The mouth has a clearance dimension d 1 . The tab  226  has a width dimension d 2  less than d 1 . When rotated 90 degrees (shown dashed as  226 ) the tab  226  has a height dimension d 3  greater than d 1  . Thus, the tab can be slid past the mouth  221  and then rotated 90 degrees as shown, thereby being captured in the channel for sliding therein. The tab provides a rounded sliding surface  226   a . In addition, a limit stop is established by a back side  223  of the mouth  221 . The channel  222  and tab  228  are configured substantially identically to operate in a substantially identical fashion as the channel  220  and the tab  226 . 
     FIGS. 7A and 7B illustrate the operation of the handle  110  within the housing  109  when configured in a press in and slide down handle operating mode. 
     In FIG. 7A, the handle  110  is illustrated in a ready state before movement. The torsion spring  244  biases the latch member in the rotational direction R. The base plate  106  includes at least one stepped wall  250  having a forward surface  248  arranged at a first distance to a rear side of the cover, a contiguous perpendicular surface  264 , and a contiguous rearward surface  266  arranged at a second distance to the rear side of the cover. The first distance is less then the second distance. 
     In the disclosed embodiment, the stepped wall  250  is formed by two parallel and substantially identical stepped wall portions  250   a ,  250   b . The latch element  164  presses the latch tip  167  to the forward surface  248  of the stepped wall  250  formed on the base plate  106 . A reaction force from the latch  164  presses the extension portion  138  of the handle  110  resiliently but firmly against the cover  108 . The stop portion  256  of the anchor member  232  is received into the stop grooves  257 ,  258  to prohibit vertical movement of the handle. 
     As shown in FIG. 7B, the handle  110  is pushed inwardly in the direction X. The front wall portion  144  has been depressed to disengage the stop grooves from the stop portion  256  of the anchor member  232 . The tabs  226 ,  228  have been slightly pivoted and slid within the channels  220 ,  222 . The handle has been slid downwardly in the direction Y guided by a base portion  270  within the slot  148 . 
     The latch tip  167  has slid across the forward surface  248 . The handle  110  has dropped below the forward surface  248  to underlie the perpendicular surface  264 , and is depressed against the rearward surface  266 . The latch  164  has been rotated clockwise by force from the torsion spring  244 . A vertical upward retraction force imparted by a person on the handle  110  would cause the latch element  164  to further rotate clockwise to a position wherein the latch end face  168  would be forced against the perpendicular surface  264 , opposing retraction of the handle. 
     FIGS. 7C and 7D illustrate the operation of the handle  110  within the housing  109  when configured in a slide down only handle operating mode. 
     In FIG. 7C, the handle  110  is illustrated in a ready state before movement. The torsion spring  244  biases the latch member in the rotational direction R. The latch element  164  presses the latch tip  167  to the forward surface  248  of the stepped wall  250  formed on the base plate  106 . A reaction force from the latch  164  presses the extension portion  138  of the handle  110  resiliently but firmly against the cover  108 . The stop portion  256  of the anchor member  232  is located on the rear side of the front wall portion  144  to prevent rearward movement of the handle. 
     As shown in FIG. 7D, the handle  110  is pushed downwardly in the direction Y guided by the base portion  270  within the slot  148 . The latch tip  167  has slid across the forward surface  248  and has dropped below the forward surface  248  to underlie the perpendicular surface  264 . The latch has been rotated clockwise by force from the torsion spring  244  and presses against the rearward surface  266 . A vertical upward retraction force imparted by a person on the handle  110  would cause the latch element  164  to further rotate clockwise to a position wherein the latch end face  168  would be faced against the perpendicular surface  264 , opposing retraction of the handle. 
     In either of the configurations of FIG. 7B or FIG. 7D, to reset the handle, the cover need only be unlocked and opened. The spring  134  will automatically retract the handle  110  upwardly. The latch  164  will move away from and disengage the stepped wall  250 . When the cover is then re-closed, the latch will be resiliently rotated slightly counterclockwise (as shown in FIGS. 7A and 7C) to assume a position with the latch tip  167  pressed against the forward surface  248 . 
     FIG. 8 illustrates the anchor member  232  oriented for a press in and slide down mode of handle operation, wherein the base portion  270  extends rearwardly of the stop portion  256 . The base portion  270  is attached to the cover by a stake  271 , formed with the cover and having a cross-shaped cross section. The stake  271  frictionally engages a channel  272  in the base portion. The channel has a matching cross-shaped cross section. 
     FIG. 9 illustrates the anchor member oriented for a slide only mode of handle operation. In this embodiment the anchor member  232  has been turned upside down and rotated 180 degrees so the stop portion  256  overlies the front wall portion  144 . The base portion  270  is attached using the stake  271  as previously described. 
     In this arrangement, the handle  110  is depressed downwardly but not inwardly. The stop portion prevents inward movement of the front wall portion  144  and guides the downward movement of the handle  110 . During sliding of the handle, the base portion  270  passes through the elongated slot  148  which guides the sliding movement, and prevents lateral movement, of the handle. 
     For more sure retention of the anchor  232 , in either embodiment of FIG. 8 or  9 , the stake  271  can be “heat staked” (i.e., mushroomed over) creating an enlarged head  271   a  to prevent unwanted removal during operation, as illustrated in FIG.  9 A. 
     FIG. 10 illustrates the latch mechanism  160  pivotally connected between the sidewalls  150 ,  152 . The torsion spring  244  surrounds the rod  166  and has a first end  244   a  pressed against and retained by a hole  150   a  in the side wall  150  and an opposite end  244   b  connected to a gusset plate  164   a  of the latch element  164 . The spring  244  is configured to urge the latch element  164  to pivot about the rod  166 . 
     The switch activating wall  172  and the switch deactivating wall  174  are shown in FIG. 10. A slot  173  is arranged between the walls  172 ,  174  in order to receive the switch lever  184  into a space between walls  172 ,  174 . The edge surface  174   a  of the wall  174  which partially defines the slot  173  can act on the switch lever to reset the switch during resetting of the pull station, i.e., the switch is automatically reset by the closing motion of the cover  108 . 
     FIGS. 11 and 12 illustrate a terminal block  300  formed on a back side of the base plate  106 . The block  300  carries a plurality of terminals  302 , advantageously at a standard spacing of 0.375 inches. Each of the terminals includes a screw contact terminal  303  and a loop solder terminal  304 . 
     The screw contact  303  is preferably configured to allow for the electrical connection of two solid wires  325 ,  326 , having a size of between 18 to 12 AWG. One of the two wires is located on each side of the screw shaft  303   a.    
     Each screw contact  303  is positioned between two barrier walls  306 ,  307 . These walls prevent the wires from shifting while the screw contact  303  with a square washer  308  is being turned. The screw contact is preferably a captivated screw having a size #8/32. 
     The loop solder terminal  304  allows for the permanent soldered connection of a wire thereto. 
     Thus, each terminal block, as illustrated, can accommodate four electrical connections. The U-shaped body  310  is formed using one continuous piece of metal. 
     FIGS. 13 and 16 further illustrate the terminals. Each has a U-shaped body  310  with an anchor portion  312  fixed into a slot  313  formed in the plastic base plate  106  by barbs  314 ,  315  and a conductor pin  316  fixed into the base plate by barbs  318 . The conductor pin  316  extends into a cylindrical hollow  319  of the base plate  106 . Pin  316  contacts a conductor inside of the pull box. The screws  303  are oriented such that they are accessible from the top of the pull box even when it is located adjacent to the electrical box. 
     FIG. 17 illustrates that the barb  314  has a leading flat surface  317  having a width  317   a . On opposing sides of the leading flat surface  317  are inclined surfaces  314   a  having an overall width  314   b  and each inclined at an angle  314   c . The back sides of the barb are inclined at an angle  314   d . Arranged adjacent to the barb  314  is a barb  315 . The barb  315  has opposing angled surfaces  315   a  having an overall width  315   b  and each inclined at an angle  315   c . The barb  315  has back sides each inclined at an angle  315   d.    
     According to the invention, the distance  315   b  is greater than the distance  314   b . As the anchor is pressed into the slot  313 , the plastic of the base plate is forced to flow over the smaller barb  314  to be opened further to assist in receiving the larger barb  315  for a fixation of the anchor into the slot. This allows each barb to be fixed sequentially, into uncut plastic. 
     According to the preferred embodiment of the invention, the anchor portion  312  has the following dimensions (inches) and angles (degrees): 
       314   b =0.230 
       314   c =45 
       314   d =105 
       315   b =0.250 
       315   c =45 
       315   d =105 
       317 =0.131 
     FIGS. 13 through 15 illustrate the case  192  which encloses a circuit board  330 . The circuit board carries the LED  210  and is electrically connected thereto. 
     The case  192  includes a cover member  193  which snap engages a base member  194 , by means of resilient hooks  195  and apertures  196  applied therebetween, and/or by resilient hooks  195  and a ledge  197  applied therebetween. When the case  192  is assembled and then pressed into the back plate  106 , a plurality of tubular connectors  340  slide into the cylindrical hollows  319  of the base plate  106  and electrically connect the terminal pins  316  to the circuit board  330 . Terminal pins  316  are oriented at 90 degrees to screws  303 . 
     It will also be understood that the connector block  300  could be mounted, for example, on a printed circuit board and used in other electrical units or applications. The type of electrical unit is not a limitation of the present invention. 
     In another embodiment, the handle  110  can be removed and replaced with a snap in bezel. The contacts from a switch or circuitry mounted in the bezel can connect into the pins of connector block  300 . Alternately, the plug-in module can include additional circuiting to carry out different, non-pull box functions. 
     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course intended to cover by the appended claims all such modifications as fall within the scope of the claims.