Patent Publication Number: US-6901703-B2

Title: Crash protection device

Description:
RELATED APPLICATION 
   This patent arises from a continuing application which claims priority under 35 U.S.C. § 120 from International Patent Application No. PCT/EP00/03363, filed Apr. 14, 2000. 

   FIELD OF THE INVENTION 
   The invention relates generally to doors, and more particularly, to a crash protection device for high-speed roller doors/gates with a high-speed roller door/gate panel or with several gate elements (e.g., door panels) arranged vertically one above the other. 
   BACKGROUND OF THE INVENTION 
   A crash protection device which reliably disengages a door or gate panel or gate elements in the event of an unintended collision of the high-speed roller door panel or gate elements with a person or vehicle is known from DE 197 26 156 A1. The high-speed roller door or gate panel or the gate elements can be re-engaged by raising the high-speed roller door panel or gate elements. 
   It has been found, however, that, in strong winds or during storms, the high-speed roller door panel or gate elements can become disengaged even though no collision has occurred. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a side area of the bottom of a high-speed roller door with a bottom bar or brace, a coupling, a guide rail, and a panel. 
       FIG. 2  shows a cross section through the high-speed roller gate along line II—II of FIG.  1 . 
       FIG. 3  is an end view taken along lines  111 — 111  of FIG.  1 . 
       FIG. 4  illustrates the structure of  FIG. 1  but shows a side area of the bottom of a roller disengaged from a cam surface. 
   

   DESCRIPTION OF THE PREFERRED EXAMPLES 
   The high-speed roller door or gate  10  shown in  FIG. 1  has a high-speed roller door or gate panel  12 , which moves in the vertical direction. As used herein, the term “panel” includes a flexible member (e.g., a curtain in a roller-type door) and/or a rigid member (e.g., a section of a sectional door). The high-speed roller door panel  12  is guided at the side in a U-shaped guide rail  14  and has reinforcing profiles (not shown) at intervals of about 50cm, extending crosswise to the direction in which the panel moves. The panel  12  also has one or more bottom members, illustratively in the form of bars or braces  16  at its lower end. The bottom bar(s)/brace(s) are connected to a guide roller  18  via a coupling described below. The guide roller  18  travels along the guide rail  14 . 
   So that the high-speed roller door panel  12  can swing out freely when a collision occurs, the bottom brace  16  is provided at both ends with rounded plastic pins  20  of polyamide, preferably in the form of round cylinders. Each of the pins  20  forms the first connector element of a coupling. When in the operating position, each plastic pin  20  is held in a respective receiving space  22 , which is open at one end. 
   The receiving space  22  is formed in a plastic block or carriage  24  of polyamide, which serves as the second connector element of the coupling. Persons of ordinary skill in the art will appreciate that a plastic block  24  and a corresponding pin  20  is provided at each bottom corner of the door. These blocks  24  and pins  20  are identical in function and structure, but oriented in opposite directions. Because of these similarities, in the interest of brevity, the remainder of this description will focus on one block  24 , one pin  20 , and one coupling therebetween. It will be understood, however, that the description is equally applicable to either block  24 , either pin  20 , and either coupling. 
   The receiving space  22  is formed in the block  24  by milling out a slot  26  and then by drilling a hole or cup  28  proceeding inward from the end surface  29  of the block. The part of the block  24  above the slot  26  is able to resiliently flex upwardly slightly relative to the part of the block  24  below the slot  26  (and/or vice versa). Thus, the slot  26  divides the block  24  into a pair of gripper arms. As shown in  FIG. 3 , the hole or milled-out area  28  has a diameter which is greater than the thickness of the material of the plastic block  24 . As a result, the receiving space  22  is open at the sides but is still able to hold the plastic pin  20  and to keep it firmly in place through a friction fit and through the holding force of the gripper arms. 
   The plastic block  24  is reduced in thickness at its end to form a profiling  30  as shown in FIG.  2 . This profiling  30  has the effect that the plastic pin  20  is surrounded to varying degrees depending on the depth to which it is inserted into the receiving space  22 . To increase the retaining force when the plastic pin  20  is fully received in the space  22  such that the end surface of the pin  20  engages a back surface  31  of the space  22 , the plastic pin  20  can have a friction coating on its end surface. 
   The depth to which the plastic pin  20  is inserted into the space  22  is controlled by a roller  32  and a camming surface or ramp  34 . In particular, as shown in  FIG. 1 , the roller  32  rides along a back surface of the guide  14  during vertical travel of the door. The camming surface or ramp  34  is mounted at the bottom of the guide  14 . When the door approaches its lowermost position, the roller  32  is cammed inward from the back surface of the guide  14  and travels along the ramp  34 . When the roller travels along the ramp  34 , the plastic block  24  is pushed inward toward the bottom bar/brace  16 , so that the plastic pin  20  becomes more deeply inserted into the space  22 . 
   When the high-speed roller door panel  12  is raised, the flexibility of the material of tbe high-speed roller door panel  12  has the effect that, despite the slit  36  which allows the panel to swing out (shown in exaggerated fashion in FIG.  1 ), the connector elements are able to move away from each other. Thus the enhanced coupling of the pin  20  and space  22  is disengaged, and the panel  12  can swing out in the event of a collision.  FIG. 4  illustrates the apparatus of  FIG. 1  under a condition in which the roller  32  been raised above the ramp  34 . such that plastic block  24  has moved outward away from the bottom bar/brace  16 .  50  that the plastic pin  20  becomes less deenlv inserted into the space  22 . The retaining force of the coupling can be controlled by the depth of the slot  26 , by the choice of material of the block  24  and/or the pin  20 , and by the ratio of the diameter of the pin  20  to the thickness of the plastic block  24 . 
   To assist the disengaging movement and for use with gate elements, a compression spring can be provided in the slot  26 . 
   The disclosed devices make available a crash protection device for a high-speed roller door which is able to withstand strong winds and storms. 
   As discussed above, the coupling automatically enters into an enhanced retention mode when the high-speed roller door panel  12  is in the lowermost position. In other words, the breakaway mechanism of the disclosed device is structured to release the door panel  12  when an external force above a first threshold is applied when the door is in an open or partially open position, and to release the door panel  12  only when an external force above a second threshold higher than the first threshold is applied when the door is in a closed or substantially closed position. As a result, without any effect on the ability of the coupling to become disengaged while the door is in operation or in the open or partially open positions, it is nevertheless ensured that the closed or substantially closed door cannot be opened unintentionally or without being noticed in a storm or in a strong wind. Because the locking device enters the enhanced retention mode automatically when the door is in the lowermost position, there is no longer any chance that ignorance of the impending arrival of such an event or forgetfulness could lead to a failure to secure the gate against a storm or strong winds. 
   The illustrated crash protection device also offers the advantage of increased security against break-ins, because it provides enhanced resistance to attempts to intentionally disengage the breakaway mechanism of the door by the application of force when the door is in the lowermost (i.e., closed) position. 
   It is preferable for the locking to be accomplished by the application of a force acting in the longitudinal direction of the bottom bar. A reliable design solution is obtained by providing a guide element in the form of a roller, which travels along a ramp to actuate the enhanced retention feature. 
   Although certain apparatus constructed in accordance with the teachings of the invention have been described herein, the scope of coverage of this patent is not limed thereto. On the contrary, this patent covers all embodiments of the teachings of the invention fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.