CALL POINTS OR BREAK GLASS UNITS

Abstract: A call point for use, for example, in fire alarm systems has a displaceable element (3) such as a sheet of plastics material which is displaceable so as to cause a switch (2) to indicate an alarm condition. A flag (7) indicates that the call point has been actuated and requires re-setting. The flag (7) is integral with the displaceable element so as to move, as the element (3) moves, from a first position where it is not seen to a second position where it is seen. This may be achieved by the flag (7) being visible in a window (6) when in the second position. The element (3) may be held by a catch (4) integral with the housing (1) of the call point when the element (3) is in the unactuated position. There may be a cam (58) on which the element (3) rests in its unactuated position, the cam being displaceable to restore the element to the unactuated position when it has moved to the actuated position. The call point may have a back plate (100) and a chassis (101) and a front cover with an electrical component (103) such as a switch for setting an address of the call point as on the front surface of the chassis.

Description: CALL POINTS OR BREAK GLASS UNITS Background of the Invention Field of the Invention This invention relates to call points or break glass units. In particular, it relates to call points for use in alarm systems, for example, fire alarm or intruder alarm systems, access control systems, or for other uses. Summary of the Prior Art Alarm systems generally comprise one or more sounders; which may be mechanical bells or electronic sounders, usually one or more detectors such as smoke detectors or heat detectors, and a central control panel. In addition, most alarm systems incorporate manual call points such that a person discovering a fire, which has not yet activated any sensors, can manually alert the system, and thereby the other occupants of the building. Call points are also used in access control systems, and other applications. The call points are most commonly of the break-glass type in which a piece of glass or other frangible material is positioned so that upon pressure being applied to the glass, the glass breaks, thus actuating the switch. The switch actuation sends an appropriate signal to the alarm system. Systems of this type work well, but clearly each time a call point is actuated, the piece of glass or other material is actually broken and must be replaced before it can be used again. This does have some advantages in that a broken frangible element is clearly seen and therefore one knows that it has been set off. As an alternative, some units include an element which is not broken but which is merely displaced upon actuation by finger pressure or similar, so that it releases the switch. The displaceable element can of course be re-used many times but must be manually repositioned after each use. Since there is no clear broken element to visually check that the unit has been actuated, it is a requirement that there be some clear indication that the unit has been actuated and awaits resetting. This is just generally done by providing a flag, generally having wording such as "alarm" on it or with some other visual indication and which is mechanically moved into a visible position when the unit is actuated. Up to now, this has been done by a complicated mechanical mechanism separate to the mechanism by which the plate is moved to instigate an alarm. Summary of the Invention The present invention arose in an attempt to provide an improved call point. According to a first aspect of the present invention there is provided a call point comprising a movable element which is displaceable so as to cause a switch to indicate an alarm condition; and a flag for indicating that the call point has been actuated and requires resetting, wherein the flag is integral with the displaceable element so as to move, as the element moves, from a first position where it is not seen, to a second position where it is seen. Preferably, the element lies behind a viewing window such that in its unactuated position the flag is not viewed through the window but when actuated, the element moves to a position in which the flag is visible through the window. The displaceable element may be arranged to pivot into the alarm position, in which case the flag may preferably be provided with wording which is generally horizontal when the displaceable element is in the alarm position . According to a second aspect of the present invention in a further aspect there is provided a call point comprising a housing, a frangible or movable element for breaking or moving under manual pressure; a switch which is actuated by movement or breakage of the element to indicate an alarm position, a spring means and a latch, wherein the latch is moulded as an integral part of the moulding. According to a third aspect of the invention there is provided a call point comprising a moveable element which is displaceable so as to cause the switch to indicate an alarm condition; and wherein a cam is provided having a part upon which the moveable element rests in an unactuated position, the cam being displaceable to reset the moveable element from its actuated to its unactuated position. According to a fourth aspect of the invention there is provided a call point comprising the features of any. two or more of the preceding claims. Preferably, a pivot and a stop rib are also provided and these are also moulded as integral components of the housing. Locations for the spring and switch may also be moulded as integral components of the housing. The spring means may be a separate or integral component . Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a front view of a call point; Figure 2 shows a cross-section through the point in a normal condition; Figure 3 shows the call point in an alarm condition; Figure 4 shows a cross-section through the call point in an alarm condition; Figures 5 to 7 show an alternative call point in, respectively, NORMAL, ALARM and RESET conditions; Figure 8 shows a vertical cross-section; Figure 9 shows a horizontal cross-section; Figures 10 (a) -(c) show a cam; and Figure 11 shows an exploded view of a call point. Detailed Description Referring to Figures 1 and 2, a call point comprises a housing 1 mounting a microswitch, or other switch device 2. A displaceable element 3, comprising a sheet, generally of a plastics material, is mounted, in the normal condition, between the microswitch and a latch . The latch 4 is preferably integrally moulded as part of the housing and is formed by an upwardly directed protrusion or finger. The latch holds the displaceable element in position so that it depresses the micro switch. A spring S is held in tension when the element is in this position. The element sits behind a viewing window 6 which is open to enable a finger to be placed through it to act upon the displaceable element to actuate the call point. The housing includes one or more recesses 20 and/or clips 21 for attaching a front panel. In embodiments of the invention, an integral part of the displaceable element forms a flag 7. In the example shown, this is formed by an extended part of the displaceable element and bears the word ALARM. Of course, other suitable wording may be used, and/or colour indication (such as the colour red) . As shown, normally the flag area is not within the viewing area 8 formed by window 6 and therefore cannot be seen. All that can be seen is a rectangular central portion of displaceable element 3 defined by the size of viewing area 8. Note that the flag may be a part which is connected to the displaceable element ( eg by a rigid link) so that it moves with the displaceable element from a position where it is not viewed, to one where it is viewed. The term 'integral' in the present specification includes such constructions. The displaceable element sits at one corner upon a pivot 9 and is spaced towards its other lower corner from a stop rib 10. Pivot 9 and stop rib 10 are also preferably integrally moulded with the housing 1, as are specific locations for the spring S and micro switch 2. Figures 3 and 4 show the call point in alarm condition. When a passer-by notices an emergency situation such as smoke or fire, he actuates the call point by depressing it inwardly as shown at A (Figure 4) . This frees the lower end of the element from the latch 4 and it is then pushed by spring S so that it pivots downwards about pivot point 9. Alternatively, the pivot point 9 could be omitted and the spring possibly positioned more centrally, or a further spring added, such that the entire plate drops. Edge II of the element drops until it abuts against stop rib 10. At this position, it does not contact microswitch 2. The microswitch is therefore released and a call point is actuated. Alternatively, in some embodiments, the spring may be omitted and gravity alone used to enable the element to drop. It is seen that as the displaceable element drops so does the part 7 of the displaceable element which acts as a flag, and this is arranged to drop sufficiently so that the alarm wording can now been seen through the viewing window 6. Thus, an observer of the call point is immediately alerted that this switch is in alarm and, after the emergency situation has passed, requires re-setting. A separate viewing window may alternatively be provided, through which the flag is visible. In a system such as that shown in which the displaceable element pivots, the flag and the associated wording are preferably printed or otherwise affixed on the displaceable element such that when the call point is in its alarm condition the wording is generally horizontal. This necessitates it being printed at a suitable angle, as shown in Figure I. One or more location lugs 12, 13 may be formed as inward projections from the housing and serve to correctly position and space the displacing element in its normal position. The housing is preferably of a plastics material and, as described, most preferably items such as the latch, pivot, stop rib and locations for the spring and micro switch are moulded as integral parts of the housing. This greatly eases manufacture and is a significant improvement over prior art designs in which separate latching components had to be manufactured and secured within the call point. Figures 5 to 10 show an alternative embodiments of the call point. In this embodiment, a displaceable or breakable element 56 also includes a flag portion 57 which is arranged to move into and out of a viewing window. The displaceable element 56 is held in a normal condition by a cam 58. This holds the element under tension from spring 55 so that micro switch 2 is depressed. The alarm flag is not seen. The cam is mounted on a pivot 59 but is prevented from rotation in the normal condition by a clip 60 (shown more clearly in Figure 8 in cross section) . This shows that the clip 60 includes an upper shoulder portion against which a surface of the cam 58 abuts when in the normal condition, preventing rotation of the cam about pivot 59. The clip 60 is preferably moulded as part of the chassis of the call point and includes a ramp portion 61 tapering outwards from the bottom, so that as a key or other member is pushed upwards, generally along the line of the ramp, it pushes the ramp progressively back, and thereby pushes back the attached clip portion. Upon noting an alarm condition, or for testing the unit, a user pushes the displaceable member roughly out of position indicated by the arrows . This causes the displaceable member to deform so that its central portion is pushed inwardly, as is shown in Figure 9. It is thus pushed away from the top part 62 of the cam and moves underneath the cutaway area 62 on the cam under downwards pressure from the spring. It comes to rest upon a ledge portion 63 of the cam. Note that the various portions of the cam are shown more clearly in Figures 10 (a) -(c) . The displaceable element is still deformed. Since the displaceable element has now been pushed, downwards, the flag area 57 is now visible within the viewing window. The micro switch 2 is now released and thus an alarm is signalled. The displaceable element pivots on the part 63 of -l i the frame . In order to reset the element, a key 70 is used (Figure 7) . The key is shaped to have a portion 71 complementary to a recessed part 72 of the cam. The key 70 is inserted and acts upon ramp part 61 to push clip 60 backwards (into the plane of the paper) . As will be appreciated from Figure 8, pushing clip 60 backwards causes the cam to be released. As the key is further inserted, part 71 pushes against the edge of recess 72 and thus rotates the cam around (clockwise) to a position past the edge of the displaceable element 56. The displaceable element 56 then resumes its normal, flat, condition, as opposed to the deformed condition which it was held previously. Upon removal of the key, the opposite edge 73 of recess 72 is pulled back to rotate the cam back to its original position. As the displaceable element is now in its flat, configuration, it is pushed upwards by upstanding portion 62 of the cam and is therefore pushed back into its original "normal" condition. Clip 60 then locks back into place and the cam is locked back into its position by the clip area 60. Microswitch 2 is again depressed. Figures 10 (a) -(c) show the cam in more detail and illustrate the upstand 62, ledge 63, recessed part 72 and a through hole 73 through which a pin or other means is inserted into the chassis, and about which the cam can rotate. The cam shape is only one of several different configurations and shapes of cams which may be used to have generally the same effect. Most call points are addressable devices. Thus, if a particular call point is actuated, it is possible to determine the address of that point on the system and therefore to know which call point has been actuated. It may also be possible to interrogate the call points from a central control unit for testing and to send messages to and from the call point. Addressing of a call point is generally achieved by using a DIL (dual-in-line) switch having a number of variations in settings of the switches to set a particular address. Call points generally comprise a back box, a chassis and a front cover, including the viewing window. The address DIL switch is conventionally located behind the chassis. On installation, the call point is bolted to a wall and left until commissioning. Then, to set the address code, the installer has to take the front cover off (usually by means of one or more screws), unbolt the chassis from the back box (usually with a plurality of bolts) and then pull the chassis out to locate the DIL switches. This can be time consuming and cumbersome . Figure 11 shows an embodiment of the present invention and shows, in exploded form, a back box 100, a chassis 101 and a front cover 102. The address DIL switch 103 is located on the front surface 104 of the chassis 101. The chassis is mounted to the back plate by bolts 105 and the front panel is simply clipped in place, using means such as the recesses and clips shown on the housing (chassis) of Figure 1. The address DIL switch 103 enables an address of the callpoint to be set by variations in its settings, as previously described. The switch 103 may be replaced by an electronic circuit which is remotely accessible from a control panel to which the callpoint is connected. The control panel sends signals to the electronic circuit which set that circuit (e.g. by setting a suitable electronic memory) to a suitable address. Thus the switch 103 represents a hardware method of setting the address and the electronic circuit (which would replace the switch 103 and be in the same location) represents a software method of setting the address . Commissioning can therefore be achieved, in embodiments of the invention, by just removing the front cover, which can be simply undipped, eg by using test key 70, and then setting the address while the chassis is still mounted on the back box. The test key has a part may have is suitably shaped, or has a suitably shaped fob portion to enable the front panel to be removed. An LED or any other indicator may be mounted in a mounting part 107 , and viewed through a hole 106 in the front panel. Other electronic apparatus and devices, including the control electronics for the call point, may also be mounted on the front face of the chassis.

Claims: CLAIMS 1. A call point comprising a displaceable element (3) which is displaceable so as to cause a switch (2) to indicate an alarm condition; and a flag (7) for indicating that the call point has been actuated and requires re-setting, characterised in that: the flag (7) is integral with the displaceable element (3) so as to move, as the element (3) moves, from a first position where it is not seen, to a second position where it is seen. 2. A call point as claimed in Claim 1, wherein the element (3) lies behind a viewing window (6) such that in its unactuated position, the flag (7) is not viewed through the window (6) but, when actuated, the element (3) moves to a position in which the flag (7) is visible through the window. 3. A call point as claimed in Claim 1 or Claim 2, wherein the element (3) is arranged to pivot into the alarm position. 4. A call point as claimed in any preceding claim, wherein the flag (7) is connected by a link to a part of the displaceable element (3) that is intended to be manually depressed. 5. A call point as claimed in any preceding claim, wherein the displaceable element (3) rests, in its unactuated position, upon a part of a chassis of the call point and, when actuated, the element no longer rests upon that part and therefore drops, or is caused to drop. 6. A call point as claimed in any of Claims 1 to 4, comprising a cam (58) having a part upon which, the displaceable element rest which in its unactuated position, said cam (58) being movable subsequently to reset the displaceable element (3) from its actuated to its unactuated position. 7. A call point as claimed in Claim 6, wherein the cam (58) is rotatable. 8. A call point as claimed in any preceding claims, wherein a reset key (70) is used to reset the position of the displaceable element (3) . 9. A call point as claimed in any of Claims 6 to 8, wherein a clip portion (60) is provided which selectably prevents the cam (58) from movement. 10. A call point as claimed in Claim 9, wherein the clip (60) is moved by insertion of a key (70) to enable movement of the cam (58) . 11. A call point comprising a housing (1), a frangible or moveable element (3) for breaking or moving under manual pressure; a switch (2) which is actuated by movement or breakage of the element (3) to indicate an alarm position, a spring (5) and a latch (4) for the element (3) , characterised in that: the latch (4) is moulded as an integral part of the housing (1) . 12. A call point as claimed in Claim 11, further comprising a pivot (9) and a stop rib (10) which are also moulded as integral components of the housing of the housing (1) . 13. A call point comprising a moveable element (3) which is displaceable from an unactuated position to an actuated position so as to cause a switch (2) to indicate an alarm condition; characterised in that: the call point has a cam (58) having a part (62) upon which the moveable element (3) rests in the unactuated position, the cam (58) being displaceable to reset the moveable element (3) from its actuated to its unactuated position. 14. A call point according to claim 13, wherein the moveable element (3) is movable from the unactuated position to the actuated position with the cam (58) stationary. 15. A call point according to claim 14, wherein said displacement of the cam (58) comprises a fist movement of the cam (58) in a first direction of course said part (62) of the cam (58) to engage an edge of the moveable element (3), and a second movement of the cam (58) in a second direction to reset the moveable element (3) . 16. A call point according to claim 15, wherein the first movement of the cam (58) is caused by the insertion of a key (70) into the call point and the second movement of the cam (58) is caused by the removal of the key (70) from the call point. 17. A call point comprising a back plate (100), a chassis (101) and a front cover (102), characterised in that: at least one electrical component (103) of the call point is mounted on the front surface of the chassis (101) . 18. A call point as claimed in Claim 17, wherein the electrical component (103) is a switch and/or an electrical circuit for setting an address of the call point . 19. A call point as claimed in Claim 17 or Claim 18, wherein the front cover (102) is mounted such that it can be removed by the insertion of a key. 20. A call point according to any one of claims 17 to 19, wherein the front cover has an opening therein, a moveable element is mounted within the front cover and being displaceable from an unactuated direction to an actuated position, and the call point has a switch which contacts the moveable element when the moveable element is in the unactuated position, and which indicates an alarm condition when the moveable element is in the actuated position.

Inventors: ANDERSON CHRISTOPHER NEIL, ANDERSON, CHRISTOPHER, NEIL
Applicants: ANDERSON CHRISTOPHER NEIL, FULLEON LTD, ANDERSON, CHRISTOPHER, NEIL, FULLEON LIMITED
Application year: 2000
Main classification: G08B25
IPC codes: G08B25