Patent Publication Number: US-2012032455-A1

Title: Press bar mechanism

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a press bar mechanism for an emergency escape or exit door or fire retardant door and exit device, and more particularly to a press bar mechanism including a buffering or cushioning or damping device for cushioning or damping the movement of the press bar and for preventing the press bar from generating sounds or noises. 
     2. Description of the Prior Art 
     Typical emergency escape or exit doors or fire retardant doors and exit devices comprise a press bar mechanism for being actuated by the user to open the emergency escape or exit door or fire retardant door. 
     For example, U.S. Pat. No. 5,816,017 to Hunt et al., U.S. Pat. No. 6,000,733 to Linder, and U.S. Pat. No. 6,945,571 to Lin disclose three of the typical press bar devices or mechanisms each comprising a press bar carried on a door panel, and coupled to a latch bolt with a crank-coupling mechanism, and/or one or more sliding members, for allowing the press bar to selectively actuate or operate the latch bolt to release or to lock or to unlock the emergency escape or exit doors or fire retardant doors and exit devices. 
     However, normally, no buffering or cushioning or damping devices or mechanisms have been provided and disposed between the press bar and the emergency escape or exit door, and the press bar may have a good chance to strike onto the emergency escape or exit door and to make or generate sounds or noises when the press bar is released by the user. 
     The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional press bar devices or mechanisms for the emergency escape or exit doors or fire retardant doors and exit devices. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a press bar mechanism including a buffering or cushioning or damping device for cushioning or damping the movement of the press bar and for preventing the press bar from generating sounds or noises. 
     In accordance with one aspect of the invention, there is provided a press bar mechanism comprising a housing, a latch bolt slidably attached to the housing, a pressing bar slidably attached to the housing and movable toward the housing and coupled to the latch bolt for selectively retracting the latch bolt into the housing, a rod slidably received in the housing and coupled to the latch bolt for selectively retracting the latch bolt into the housing, and including an extension extended therefrom, a hydraulic buffering device including a casing having a first end coupled to the housing and having a chamber formed in the casing for receiving a hydraulic fluid therein, a piston slidably engaged in the chamber of the casing and movable toward or away from the first end of the casing, the piston including at least one orifice formed therein for allowing the fluid to selectively flow through the orifice of the piston, and the piston including an outer diameter smaller than an inner diameter of the casing for forming a peripheral passage between the casing and the piston and for allowing the fluid to selectively flow through the peripheral passage that is formed between the casing and the piston, a piston rod attached to the piston and extended out of the casing and coupled to the extension of the rod for allowing the piston rod and the piston to be moved relative to the casing by the rod, and a valve member attached to the piston for selectively blocking the orifice of the piston and for preventing the fluid from flowing back through the orifice of the piston, and a spring biasing member for biasing the rod toward the casing and the latch bolt and for biasing the pressing bar away from the housing, the extension of the rod is moved away from the casing, and the piston being moved away from the first end of the casing by the piston rod and the rod when the pressing bar is depressed and moved toward the housing, and the extension of the rod is moved toward the first end of the casing when the pressing bar is released such that the movement of the press bar may be cushioned and such that the press bar may be prevented from generating sounds or noises. 
     The housing includes a frame disposed and secured therein, and the first end of the casing is pivotally secured to the frame with a pivot axle. 
     The housing includes a crank pivotally coupled to the frame and pivotally coupled to the latch bolt with a link and pivotally coupled to the pressing bar. 
     Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial cross sectional view of a press bar mechanism in accordance with the present invention; 
         FIG. 2  is a partial cross sectional view similar to  FIG. 1 , illustrating the operation of the press bar mechanism; 
         FIG. 3  is a partial exploded view illustrating a portion of the press bar mechanism; 
         FIG. 4  is a perspective view illustrating the portion of the press bar mechanism as shown in  FIG. 3 ; 
         FIG. 5  is a perspective view illustrating a hydraulic buffering or cushioning or damping device of the press bar mechanism; 
         FIG. 6  is a cross sectional view of the hydraulic buffering or cushioning or damping device, taken along lines  6 - 6  of  FIG. 5 ; 
         FIG. 7  is an enlarged partial cross sectional view of the hydraulic buffering or cushioning or damping device of the press bar mechanism; 
         FIG. 8  is another cross sectional view similar to  FIG. 6 , illustrating the operation of the hydraulic buffering or cushioning or damping device of the press bar mechanism; and 
         FIG. 9  is an enlarged partial cross sectional view of the hydraulic buffering or cushioning or damping device as shown in  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, and initially to  FIGS. 1 and 2 , a press bar mechanism  1  in accordance with the present invention comprises a base or housing  10  for attaching to an emergency escape door or fire retardant door and exit device or exit door panel (not shown), and a pressing bar  11  slidably attached to the housing  10  and movable or depressible toward the housing  10  for being selectively depressed or actuated by the user, and one or more coupling or spring members  12  disposed or attached between the pressing bar  11  and the exit door panel for biasing or forcing the pressing bar  11  away from the exit door panel and the housing  10  when the pressing bar  11  is released by the user. 
     A lock device  20  is attached to the housing  10  and includes a latch bolt  21  for selectively releasing or locking or unlocking the exit door panel, and includes a frame  22  disposed or attached or secured to the housing  10 , a crank  23  rotatably or pivotally coupled to the frame  22  or the housing  10  with a pivot axle  24  and pivotally coupled to the latch bolt  21  with a link  25  and also pivotally coupled to the pressing bar  11  for allowing the latch bolt  21  to be selectively moved or retracted into the housing  10  when the pressing bar  11  is depressed toward the housing  10  by the user, and for allowing the exit door panel to be selectively opened. The above-described structure or arrangement is typical and will not be described in further details. 
     As shown in  FIGS. 1-4 , a longitudinal beam or rod  30  is slidably received in the housing  10 , and includes one end  31  pivotally coupled to the crank  23  and/or the link  25  and/or the latch bolt  21  to selectively move or retract the latch bolt  21  into the housing  10 , and includes a stop or plate or extension  32  extended radially or outwardly from the rod  30 , or the extension  32  includes one end  33  attached or mounted or secured to the rod  30  with one or more latches or fasteners  34  and includes another end  35  located or extended away from the rod  30 . A spring biasing member  36  may further be provided and engaged with or between the rod  30  and the housing  10  for biasing the rod  30  toward the lock device  20  and the latch bolt  21 , and for biasing the latch bolt  21  to engage with the exit door panel, and also for biasing the pressing bar  11  away from the housing  10 . 
     A hydraulic buffering or cushioning or damping device  5  is further be provided and includes a cylindrical casing  50  having one end or first end  51  pivotally or rotatably attached or mounted or secured or coupled to the housing  10 , such as coupled to the frame  22  of the housing  10  with a pivot axle  37 , as shown in  FIGS. 5-9 , the casing  50  includes a bore or chamber  52  formed therein for receiving a hydraulic oil or fluid  53  therein. A piston  54  is slidably received or engaged in the chamber  52  of the casing  50  and movable toward or away from the first end  51 , and includes one or more orifices  55  formed therein for allowing the fluid  53  to selectively flow through the orifices  55  of the piston  54  ( FIGS. 6 ,  7 ), and includes an outer diameter slightly smaller than the inner diameter of the casing  50  for forming or defining a peripheral gap or passage  56  between the casing  50  and the piston  54  ( FIGS. 7 ,  9 ) and for also allowing the fluid  53  to selectively flow in either direction through the peripheral passage  56  that is formed between the casing  50  and the piston  54 . 
     A spring blade or check valve member  57  is attached or mounted or secured to the piston  54  with a piston rod  58  and a fastener  59  for selectively blocking the orifices  55  of the piston  54  ( FIGS. 8 ,  9 ) and for preventing the fluid  53  from flowing through the orifices  55  of the piston  54 , such that the spring blade or check valve member  57  may act as a spring biasing means or check valve means or device for limiting the fluid  53  to selectively flow through the orifices  55  of the piston  54  in one direction only and for preventing the fluid  53  from flowing through the orifices  55  of the piston  54  in the other or opposite direction. The piston rod  58  has a free end or outer end extended out of the casing  50  and attached or mounted or secured or coupled to the upper or other end  35  of the extension  32  of the rod  30  for allowing the piston rod  58  and the piston  54  to be moved relative to the casing  50  by the extension  32  of the rod  30 . 
     In operation, as shown in  FIG. 2 , when the pressing bar  11  is selectively depressed or actuated by the user and moved toward the housing  10 , the latch bolt  21  may be selectively moved or retracted into the housing  10  by the crank  23 , and simultaneously, the rod  30  may be selectively moved away from the lock device  20  by the crank  23 , and the extension  32  of the rod  30  may also be moved away from the lock device  20  and the casing  50  of the buffering or cushioning or damping device  5 . At this moment, the piston  54  may be moved or pulled or forced to move away from the lock device  20  by the piston rod  58  and may be moved slowly by the spring biasing member  36  and by the buffering and flowing of the fluid  53  through the orifices  55  of the piston  54  ( FIGS. 6 ,  7 ). 
     When the pressing bar  11  is released by the user, as shown in  FIG. 1 , the pressing bar  11  may be moved or forced or biased away from the exit door panel and the housing  10  by the spring biasing member  36 , and the latch bolt  21  may be moved or forced out of the housing  10  to engage with the exit door panel and to lock the exit door panel. At this moment, the extension  32  of the rod  30  may be moved or forced to engage with the piston rod  58  and to force the piston  54  to move toward the first end  51  of the casing  50  and to move toward the lock device  20  and the latch bolt  21 . At this moment, the spring blade or check valve member  57  may block the orifices  55  of the piston  54  ( FIGS. 8 ,  9 ) and may prevent the fluid  53  from flowing through the orifices  55  of the piston  54 , and the fluid  53  may selectively flow through the peripheral passage  56  that is formed between the casing  50  and the piston  54 , such that the hydraulic buffering or cushioning or damping device  5  may be provided for buffering or cushioning or damping or slowing the movement of the press bar  11  and for preventing the press bar  11  from generating sounds or noises. 
     Accordingly, the press bar mechanism in accordance with the present invention includes a buffering or cushioning or damping device for cushioning or damping or slowing the movement of the press bar and for preventing the press bar from generating sounds or noises. 
     Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.