Spring-loaded post extension for resilient support of ceiling grids during seismic events

Abstract

A spring-loaded post extension for resilient support of ceiling grids during seismic events. The post extension includes a fixed cylindrical housing and a movable spring-biased assembly, axially coincident therewith. The housing is connected to the side of a fixed support post. The assembly includes a support tube extending partly within the lower end of the cylindrical housing. The bottom of the support tube is connected to a ceiling grid junction. A threaded rod has an upper portion extending above the upper end of the housing, and a lower portion extending through the housing to connect to the top of the support tube. An exterior spring fits over the upper portion of the rod, and an interior spring fits over the lower portion of the rod. Nuts on the rod provide means to tension both springs into slight compression, defining a spring-biased normal position for the support tube.

1 . A post extension for resiliently supporting ceiling grids during seismic events, comprising:
 a. a fixed cylindrical housing;   b. a movable spring-biased assembly, said cylindrical housing and said assembly being axially coincident, said assembly including: a support tube having an upper section extending partly within a lower end of said cylindrical housing; a threaded rod, said threaded rod having an upper portion extending above an upper end of said housing, and further having a lower portion extending through said housing to connect to a top of said support tube; an exterior spring fitting over said upper portion of said rod; an interior spring fitting over said lower portion of said rod; and,   c. means to tension said exterior spring and said interior spring into compression against said upper end of said housing, defining a spring-biased normal position for said support tube.   
   
   
       2 . A post extension as in  claim 1  including flanges along an outer wall of said cylindrical housing, for attachment to the side of a fixed support post. 
   
   
       3 . A post extension as in  claim 1  including attachment ears adjacent a lower end of said cylindrical housing. 
   
   
       4 . A post extension as in  claim 1  in which said means to tension said exterior and interior springs comprises bolts and washers on said upper portion and said lower portion of said threaded rod. 
   
   
       5 . A post extension as in  claim 1  in which said support tube includes a lower section provided with ceiling grid connection means. 
   
   
       6 . An apparatus for resilient support of a suspended ceiling grid during a seismic event, comprising:
 a. a fixed support post extending vertically and downwardly from a ceiling;   b. a post extension including a fixed cylindrical housing and a movable spring-biased assembly, said cylindrical housing and said spring-biased assembly being elongated and axially coincident, said cylindrical housing including flanges along an outer wall for connection to a side of said support post and further including a plurality of attachment ears on a lower end of said housing;   c. opposing bias means for resiliently interconnecting said housing and said spring-biased assembly into a normal position, allowing axial excursions of said assembly with respect to said housing in either direction; and,   d. a plurality of guy wires extending vertically in diverging fashion from said attachment ears to the ceiling.   
   
   
       7 . An apparatus as in  claim 6  in which said spring-biased assembly further includes a support tube having an upper section extending partly within a lower end of said cylindrical housing. 
   
   
       8 . An apparatus as in  claim 7  in which said support tube includes a lower section provided with ceiling grid connection means. 
   
   
       9 . An apparatus for resilient support of a suspended ceiling grid during a seismic event, comprising:
 a. a plurality of fixed support posts extending vertically and downwardly from a ceiling;   b. a plurality of post extensions, each said post extension including a fixed cylindrical housing and a movable spring-biased assembly, said cylindrical housing and said spring-biased assembly being elongated and axially coincident, said cylindrical housing including flanges along an outer wall for connection to a side of a respective said support post and further including a plurality of attachment ears on a lower end of said housing;   c. opposing bias means for resiliently interconnecting each said housing and each said spring-biased assembly into a normal position, allowing axial excursions of each said assembly with respect to a respective said housing in either direction; and,   d. a plurality of guy wires extending vertically in diverging fashion from each of said attachment ears to the ceiling.   
   
   
       10 . An apparatus as in  claim 9  in which each said spring-biased assembly further includes a support tube having an upper section extending partly within a lower end of a respective said cylindrical housing. 
   
   
       11 . An apparatus as in  claim 10  in which each said support tube includes a lower section provided with ceiling grid connection means. 
   
   
       12 . A post extension for resiliently supporting ceiling grids during seismic events, comprising:
 a. an elongated fixed cylindrical housing having a side wall and a lower end, said cylindrical housing including flanges along said outer wall for connection to a support post and further including a plurality of attachment ears on said lower end;   b. an elongated support tube having an upper section extending partly within said lower end of said cylindrical housing, said support tube and said cylindrical housing being axially coincident; and,   c. opposing bias means for resiliently interconnecting said housing and said spring-biased assembly into a normal position, allowing axial excursions of said support tube with respect to said cylindrical housing in either direction.   
   
   
       13 . An apparatus as in  claim 12  in which said opposing bias means comprises: a threaded rod, said threaded rod having an upper portion extending above an upper end of said housing, and further having a lower portion extending through said housing to connect to a top of said support tube; an exterior spring fitting over said upper portion of said rod; and, an interior spring fitting over said lower portion of said rod. 
   
   
       14 . An apparatus as in  claim 13  further including bolts and washers on said upper portion and said lower portion of said threaded rod to tension said exterior spring and said interior spring into compression against said upper end of said housing. 
   
   
       15 . An apparatus as in  claim 14  in which said support tube includes a lower section provided with ceiling grid connection means. 
   
   
       16 . An apparatus as in  claim 15  further including a fixed support post extending vertically and downwardly from a ceiling, said flanges on said cylindrical housing being connected to said support post. 
   
   
       17 . An apparatus as in  claim 12  further including a plurality of guy wires extending vertically in diverging fashion from each of said attachment ears to a ceiling.