Address setting means for fire detectors

Abstract

A fire detector assembly comprises a base ( 1 ) and a sensor ( 5 ) adapted to fit the base. The base ( 1 ) is provided with passive means, such as pins ( 6 ) or contacts arranged in a pattern to represent an address of the detector. When the sensor ( 5 ) is fitted to the base ( 1 ), reading means in the sensor reads the address code and thereby conditions the sensor to receive appropriate signals from a control unit.

We claim:  
     
       1. An addressable fire detector assembly for receiving address coded signals from a central control, said assembly comprising a base and a sensor, said base and said sensor having means which enable them to be fitted together to form said assembly, said base having passive means to define an address code, the passive means being formed only by mechanical means for storing the address code, said sensor having means for reading said address code and for conditioning said sensor to receive said address coded signals from said central control  whereby the address code is read when the sensor is fitted to the base and the sensor is thereby conditioned to receive signals from the central control. 
     
     
       2. An assembly according to claim  1  wherein said passive means comprises a plurality of elements in a particular arrangement in a given region, the reading means in the sensor being capable of detecting the presence or absence of said elements in said region. 
     
     
       3. An assembly according to claim  2  wherein said elements are mechanical elements. 
     
     
       4. An assembly according to claim  3   1 wherein the reading means includes switching elements which are operated by the mechanical elements where present. 
     
     
       5. An assembly according to claim  4  wherein the switching elements include a plurality of leaf springs mounted on a common conductive member, the sensor including a printed circuit having contact pads thereon which are engaged by the leaf springs that are operated by the mechanical elements where present. 
     
     
       6. An assembly according to claim  1  wherein the passive means comprise electrical contacts on said base, the reading means being provided with electrical contacts for making respective electrical connections with the contacts on the base and including circuitry which is responsive to said electrical connections in order to read the address code. 
     
     
       7. An assembly according to claim  1  wherein the passive means is arranged to represent a binary address code. 
     
     
       8. An addressible fire detector assembly according to claim  1  wherein the passive means are attached to a card-shaped member which is received in guides on the base, the card-shaped member having either a recess or key for cooperating with a respective key or recess on the sensor when the sensor is of a designated type to be fitted to the base, the arrangement also being such that a catch secures the member to the base when the member is fitted to the base and that the sensor makes the catch inaccessible when the sensor is fitted to the base. 
     
     
       9. An assembly according to claim  1  wherein the sensor includes a memory for storing the address code read from the passive means. 
     
     
       10. An addressible fire detector assembly according to claim  1  wherein the passive means are removably fitted to the base either individually or collectively. 
     
     
       11. An addressible fire detector assembly according to claim  10  wherein the passive means are part of a member which is secured against removal from the base when the member has been fitted to the base. 
     
     
       12. An addressible fire detector assembly according to claim  1  wherein the base is provided with means which cooperate with the sensor to enable only a sensor of a designated type to be fitted to the base. 
     
     
       13. An addressible fire detector assembly according to claim  12  wherein a part of said means is on a member to which the passive means are attached, said member being removably fitted to the base. 
     
     
       14. An addressible fire detector assembly for receiving address coded signals from a central control, said assembly comprising a base and a sensor having means which enable them to be fitted together to form said assembly, said base also having mechanical means for defining a bar code, said sensor having means for reading said bar code and for conditioning said sensor to receive said address coded signals. 
     
     
       15. An addressible fire detector assembly for receiving address coded signals from a central control, said assembly comprising a base and a sensor, said base and said sensor having means which enable them to be fitted together to form said assembly, said base also having a plurality of address coding pins, said pins being spatially disposed for physically defining an address code to identify said assembly, said sensor having a plurality of switchable elements, which are spatially disposed for actuation by said address coding pins when said sensor is fitted to said base, said sensor further including circuitry responsive to said switching elements for reading and storing said address code whereby said assembly is conditioned to respond only to said address code signals containing said address code defined by said pins. 
     
     
       16. An addressible fire detector assembly according to claim  15  wherein said address coding pins are provided on a card, said card being removably fitted to said base, said base further including means for locating said card in a predetermined reading position at which said address code can be read. 
     
     
       17. An addressible fire detector assembly according to claim  16  wherein said card is provided with a predetermined edge profile and wherein said sensor is provided with abutment means to engage the predetermined edge profile of said card when said sensor is fitted to said base, said edge profile and said abutment means being disposed so as to enable only a sensor of a predetermined type to be fitted to said base in which said card is located in said reading position. 
     
     
       18. An addressable fire detector assembly for receiving address coded signals from a central control, said assembly comprising a base and a sensor, said base and said sensor having engaging surfaces configured to enable said base and said sensor to be fitted together to form said assembly, said base having a plurality of passive mechanical coding pins defining an address code, each of said plurality of mechanical coding pins having an engaging surface, the address code being stored only by said passive mechanical coding pins, said sensor having a plurality of mechanical reading pins, each responding to said engaging surface of a corresponding one of said plurality of mechanical coding pins to read said address code whereby the address code is read when the sensor is fitted to said base and sensor is thereby conditioned to receive signals from the central control.