Silencer for exhaust systems

Abstract

A silencer 1 for an exhaust system comprising a fluid outlet ( 14, 5 ) and control means for opening and closing the fluid outlet ( 14, 5 ). The control means may comprise a bi-metallic strip ( 2 ) with a rivet stopper ( 22 ) at one end. The fluid outlet may comprise an aperture ( 14 ) or a self-tapping plug ( 5 ).

1 . A silencer for an exhaust system comprising a fluid outlet and control means for opening and closing the fluid outlet.  
   
   
       2 . A silencer according to  claim 1  arranged such that when the exhaust system is in use, the fluid outlet is opened by the control means and when the exhaust system is idle, the fluid outlet is closed by the control means.  
   
   
       3 . A silencer according to  claim 1  arranged such that when the exhaust system is in use, the fluid outlet is closed by the control means and when the exhaust system is idle, the fluid outlet is opened by the control means.  
   
   
       4 . A silencer according to  claim 1  wherein the fluid outlet is an aperture formed in the casing of the silencer.  
   
   
       5 . A silencer according to  claim 1  wherein the fluid outlet is a self-tapping plug.  
   
   
       6 . A silencer according to  claim 1  wherein the control means comprises temperature dependent control means arranged to open and close the fluid outlet in dependence on the temperature of the silencer.  
   
   
       7 . A silencer according to  claim 6  wherein the temperature dependent control means comprises a bi-metallic strip.  
   
   
       8 . A silencer according to  claim 4  wherein the control means comprises a plug for closing the aperture.  
   
   
       9 . A silencer according to  claim 1  wherein the control means is provided adjacent an internal surface of the silencer.  
   
   
       10 . A silencer according to  claim 1  wherein the control means is provided adjacent an external surface of the silencer.  
   
   
       11 . A silencer according to  claim 7  wherein the bi-metallic strip is held at one end such that a free end of the bi-metallic strip is movable by varying the temperature of the bi-metallic strip.  
   
   
       12 . A silencer according to  claim 11  wherein the bi-metallic strip is substantially straight.  
   
   
       13 . A silencer according to  claim 11  wherein the bi-metallic strip is arched.  
   
   
       14 . A silencer according to  claim 7  further comprising a second bi-metallic strip.  
   
   
       15 . A silencer according to  claim 14  wherein the second bi-metallic strip is attached to the first bi-metallic strip at least one point.  
   
   
       16 . A silencer according to  claim 14  wherein at least one temperature the second hi-metallic strip is tensioned against the first bi-metallic strip.  
   
   
       17 . A silencer according to  claim 7  wherein the bi-metallic strip is held in at least two locations such that the bi-metallic strip may arch.  
   
   
       18 . A silencer according to  claim 17  wherein the control means is arranged such that when the bi-metallic strip is at a first temperature, the bi-metallic strip is substantially flat causing the fluid outlet to be closed and when the bi-metallic strip is at a second temperature the bi-metallic strip is arched causing the fluid outlet to be opened.  
   
   
       19 . A silencer according to  claim 18  wherein the first temperature is higher than the second temperature.  
   
   
       20 . A silencer according to  claim 18  wherein the second temperature is higher than the first temperature.  
   
   
       21 . A silencer according to any preceding  claim 1  comprising a cover to protect the control means.  
   
   
       22 . A silencer according to  claim 21  wherein the cover comprises a bi-metallic cover strip.  
   
   
       23 . A silencer according to  claim 22  arranged such that the bi-metallic cover strip adopts a flatter configuration when the fluid outlet is closed and a more arched configuration when the fluid outlet is open.  
   
   
       24 . A method of adapting a silencer for an exhaust system, comprising the steps of: 
 providing the silencer with a fluid outlet; and    providing silencer control means for opening and closing the fluid outlet.    
   
   
       25 . A method according to  claim 24  further comprising the step of arranging the control means such that when the exhaust system is in use, the fluid outlet is opened by the control means and when the exhaust system is idle, the fluid outlet is closed by the control means.  
   
   
       26 . A method according to  claim 24  further comprising the step of arranging the control means such that when the exhaust system is in use, the fluid outlet is closed by the control means and when the exhaust system is idle, the fluid outlet is opened by the control means.  
   
   
       27 . A method according to  claim 24  wherein the step of providing the silencer with a fluid outlet comprises the step of forming an aperture in the casing of the silencer.  
   
   
       28 . A method according to  claim 24  wherein the step of providing the silencer with a fluid outlet comprises the step of inserting a self-tapping plug.  
   
   
       29 . A method according to  claim 24  wherein the step of providing the silencer with control means comprises the step of providing temperature dependent control means arranged to open and close the fluid outlet in dependence on the temperature of the silencer.  
   
   
       30 . A method according to  claim 29  wherein the temperature dependent control means comprises a bi-metallic strip.  
   
   
       31 . A method according to  claim 27  wherein the control means comprises a plug for closing the aperture.  
   
   
       32 . A method according to  claim 24  comprising the step of providing the control means adjacent an internal surface of the silencer.  
   
   
       33 . A method according to  claim 24  wherein including the step of providing control means adjacent an external surface of the silencer.  
   
   
       34 . A method according to  claim 30  wherein the bi-metallic strip is held at one end such that a free end of the bi-metallic strip is movable by varying the temperature of the bi-metallic strip.  
   
   
       35 . A method according to  claim 34  wherein the step of providing a bi-metallic strip is the step of providing a substantially straight bi-metallic strip.  
   
   
       36 . A method according to  claim 34  wherein the step of providing a bi-metallic strip is the step of providing an arched bi-metallic strip.  
   
   
       37 . A silencer according to  claim 30  further comprising the step of providing a second bi-metallic strip.  
   
   
       38 . A method according to  claim 37  comprising the step of attaching the second bi-metallic strip to the first bi-metallic strip at least one point.  
   
   
       39 . A method according to  claim 37  comprising the step of tensioning the second bi-metallic strip against the first.  
   
   
       40 . A method according to  claim 30  wherein the bi-metallic strip is held in at least two locations such that the bi-metallic strip may arch.  
   
   
       41 . A method according to  claim 40  comprising the step of arranging the control means such that when the bi-metallic strip is at a first temperature, the bi-metallic strip is substantially flat causing the fluid outlet to be closed and when the bi-metallic strip is at a second temperature the bi-metallic strip is arched causing the fluid outlet to be opened.  
   
   
       42 . A method according to  claim 41  wherein the first temperature is higher than the second temperature.  
   
   
       43 . A method according to  claim 41  wherein the second temperature is higher than the first temperature.  
   
   
       44 . A method according to  claim 24  comprising the step of providing a cover to protect the control means.  
   
   
       45 . A method according to  claim 44  wherein the step of providing a cover comprises the step of providing a bi-metallic cover strip.  
   
   
       46 . A method according to  claim 45  comprising the step of arranging the silencer such that the bi-metallic strip cover adopts a flatter configuration when the fluid outlet is closed and a more arched configuration when the fluid outlet is open.  
   
   
       47 . A silencer for an exhaust system comprising a fluid outlet and a control for opening and closing the fluid outlet.  
   
   
       48 . A method for adapting a silencer for an exhaust system, comprising the steps of: 
 providing the silencer with a fluid outlet; and    providing a silencer control for opening and closing the fluid outlet.