Patent Publication Number: US-2010122598-A1

Title: Pinion

Description:
The invention relates to a pinion, which corresponds to a toothed piston of a door closer or of a door operator and has at least one toothing and, at each end of the pinion, a square shaft end, at which at least one taper is provided, and a cylindrically shaped area is disposed between each square shaft end and the toothing. The position of the toothing is aligned with the two square shaft ends. 
     In the door closers as well as the door operators, which are currently available on the market and provided with pinions and toothed pistons, pinions are used which are manufactured in several operational steps at high production expenses and cost as well as high investments in machine equipment. The blank is a turned component, which subsequently is provided with a toothing. As a result, the thus manufactured pinions require that, after each operational step, the item in question be transported and stored temporarily if required, which entails a logistic challenge and logistic expenses. The cooperation of the pinion with a toothed piston is illustrated in the document DE 195 38 482 C2, as well as in DE 102 28 870 A1. 
     It is the object of the present invention to provide a pinion of the species described in the introduction, in which the toothing is mounted position-oriented with regard to the two square shaft ends. 
     As the solution to this problem, a pinion is proposed having the features of claim  1 . Preferred further developments are set forth in the dependent claims. 
     In the inventive pinion, it is intended that the toothing be mounted position-oriented with regard to the two square shaft ends located at the respective ends of the pinion. Thereby, when installing the door closer or the door operator, a pretension can be applied to the piston and thus to the spring (force accumulator) of the door closer or of the door operator. 
     It is of advantage that the pinion be manufactured as a cold extruded component. This allows for manufacturing the pinion in a single operational step. 
     Another practical embodiment is to have the toothing extend continuously. Door closers or door operators, in which the axle mounting is located in the area of the piston, can be equipped with this embodiment. This would be the case of a door closer having a small constructional height. 
     It is advantageous that the toothing has a collar at one end. The collar stabilizes the toothing. Door closers or door operators, in which the axle mounting is located outside the piston, can be equipped with this embodiment. 
    
    
     
       The drawings show: 
         FIG. 1 : an inventive pinion in a plane view, 
         FIG. 2 : the inventive pinion of  FIG. 1  in a perspective view, 
         FIG. 3 : an inventive pinion of  FIG. 1  with a collar at one end of the toothing, 
         FIG. 4 : the inventive pinion of  FIG. 3  in a perspective view, 
         FIG. 5 : an inventive pinion of  FIG. 1  in a lateral view, 
         FIG. 6 : an inventive pinion of  FIG. 1  in an installed situation with a lever arm of a door closer or of a door operator. 
     
    
    
       FIG. 1  shows a pinion  1 , which is intended for door closers as well as for door operators. In this case, it is about diverse door closers and door operators, which have a pinion as well as a toothed piston, as illustrated according to the documents DE 195 38 482 C2 and DE 102 28 870 A1. At each end, the pinion  1  has a square shaft end  4   a  and  4   b . Threaded bores  5   a  and  5   b  are provided at the frontal sides  11   a  and  11   b , which bores are not manufactured in one operational step during the production of the pinion  1 . The threaded bores  5   a  and  5   b  as well as appropriate threads are manufactured in another operational step. A toothing  2  is provided at the circumference of the pinion  1  in the middle area of the pinion  1  in the direction of the central axis  10 . At the two ends, this toothing  2  is limited by respective shafts  3   a  and  3   b , which have a smaller diameter than the inner partial circle of the toothing  2 . The pinion  1  has a central axis  10 , which serves to determine the position of the toothing  2 , of the shafts  3   a  and  3   b , of the square shaft ends  4   a  and  4   b , as well as of the threaded bores  5   a  and  5   b . At one end, the toothing  2  has a leading slope  2   a , whereas, at the other end of the toothing  2 , a continuous toothing  2   b  is provided. The pinion  1  with a continuous toothing  2   b  is used with door closers or door operators, in which the axle mounting is installed centrally with regard to the piston of the door closer or of the door operator. 
       FIG. 2  shows the pinion  1  of  FIG. 1  in a perspective view. A taper  12   a ,  12   b  is mounted on two opposite sides of the square shaft ends  4   a  and  4   b  at the respective ends of the pinion  1 . 
       FIG. 3  shows the pinion  1  of  FIG. 1 , where a collar  6  is provided at one end of the toothing  2 , to represent a non-continuous toothing. In case of stress on the pinion  1 , the collar  6  serves to stabilize the toothing  2 . The pinion  1  with a collar  6  is used with door closers or door operators, which have an axle mounting outside or centrally of the piston of a door closer or of a door operator. 
       FIG. 4  shows the pinion  1  of  FIG. 3  in a perspective view. The collar  6  is mounted to one end of the toothing  2 . The tapers  12   a  and  12   b  are mounted at two opposite sides of the square shaft ends  4   a  and  4   b  located at the respective ends of the pinion  1 . 
       FIG. 5  shows the pinion  1  of  FIG. 1  in a lateral view. This view shows that the toothing  2  is aligned position-oriented with regard to the square shaft end  4   a . The position-orientation of the toothing  2  may be embodied in a way that a plain tooth of the toothing  2  is positioned on one of the frontal-sided central lines  10   a . In another possible embodiment, the toothing  2  may be aligned such that the recess of a tooth of the toothing  2  is located on one of the frontal-sided central lines  10   a . This applies to toothings that have both an even number and an uneven number of teeth at the toothing  2  of the pinion  1 . 
       FIG. 6  shows the pinion  1  of the  FIG. 1  in a mounted situation with a lever  7  of a door closer or of a door operator. The lever  7  is positively and non-positively connected to the pinion  1  with an attachment screw  8  and a washer  9  by means of the threaded bore  5   b  (see  FIG. 1 ), which bore is manufactured in addition to the corresponding thread in another operational step. 
     The pinion  1 , made from a blank, which is a turned component, is manufactured as a cold extruded component in one operational step, which is executed in several press steps without having to rechuck the blank (turned component). In this step, the square shaft ends  4   a ,  4   b , the tapers  12   a ,  12   b , the shafts  3   a ,  3   b  and the toothing  2  with the leading slope  2   a  as well as the collar  6  are manufactured. In this case, the position of the toothing  2  is aligned at the same time with regard to the square shaft ends  4   a  and  4   b . Based on the required embodiments of the toothing  2  at the pinion  1 —toothing with continuous toothing  2   b  or toothing with collar  6 —the pinion  1  is thus manufactured as a cold extruded component. In the embodiment with a continuous toothing  2   b  additional press steps are realized. 
     The threaded bores  5   a  and  5   b  and the respectively associated threads are realized in another operational step, in order to be able to non-positively attach the pinion  1  at the lever  7  by means of the attachment screw  8  and the washer  9 , whereby the lever  7  is positively connected by means of the tapers  12   a  and  12   b  at the square shaft ends  4   a  and  4   b  of the pinion  1 . 
     LIST OF REFERENCES 
     
         
           1  pinion 
           2  toothing 
           2   a  leading slope 
           2   b  continuous toothing 
           3   a  shaft 
           3   b  shaft 
           4   a  square shaft end 
           4   b  square shaft end 
           5   a  threaded bore 
           5   b  threaded bore 
           6  collar 
           7  lever arm 
           8  attachment screw 
           9  washer 
           10  central axis 
           10   a  frontal-sided central lines 
           11   a  front side 
           11   b  front side 
           12   a  taper 
           12   b  taper