DE3638353A1 - Door closing mechanism with sprung piston - Google Patents

Abstract

The door closer housing contains a piston working with a closer spring and hydraulic damper and geared to a closer shaft by a pinion whose lever arms vary in length round the pinion circumference. The pinion side (25) gearing and/or the complementary toothing (27) for the pinion (25) should vary in profile displacement via their roll curve (26,28) and/or this should vary their modulus and/or vary their flank angle using one or more asymmetrical teeth having a more acute flank angle on the pressure side than on the non-pressure side. Pref. the profile displacement of the pinion (25) is negative in one sector of the roll curve (26), thus ensuring a small door opening angle. It can instead be positive in one sector (26), thus ensuring a large door opening angle.

Description

The invention relates to a door closer with one in one Housing guided piston, at least one cooperating with the piston Closer spring and a hydraulic damping device and with a via a gearbox with the piston connected closer shaft or closer axis.

From DE-GBM 17 95 135 is a closer of this type known.

This known closer is designed such that the torque acting on the closer shaft Maximum in the zero position, in the range of the small Opening angle decreases rapidly, then approximately the same remains and eventually gradually zero at one Opening angle drops by 180 °. This is achieved in that the closing spring on a fixed in the Closer housing arranged hollow cylinder is guided and in slots at the ends of each one as Abutment-serving slider slidable in this way is that the slide facing the closer axis by means of a roller on one on the closer axis seated cam and the other Slider connected to a crank by a handlebar is that in the opposite of the closer axis End of the housing stored and with the closer axis is non-positively connected by a chain drive.

This known device is extraordinary complex and on the other hand offers only few possibilities with regard to the specification of a specific closing force curve.  

The gear ratio of the respective NO contact, d. H. the instantaneous ratio of the angular velocity the closer axis to the angular velocity of the In practice, the door must be given great attention, especially when there are closers, be it overhead door closers or floor closer, special requirements be put. This is the case with, for example so-called slide arm closers, in which the closing torques are unfavorable because with a small opening angle, if the door needs to be pushed into the lock, only a comparatively small moment is available. Although with slide arm closers, which are characterized by an optical distinguish favorable appearance, the friction ratio at the moment of opening the wing is favorable because at small opening angle little friction arises always accepted relatively long guide rails to ensure the required functional safety.

The object of the invention is one as both an overhead door closer as well as bottom door closers and in particular to create door closers that can be used as slide arm closers, of both the demands for compact design and economical manufacturing possibility as well as the claim with regard to functionally optimal closing torques and accordingly the use of short, the dimensions correspond approximately to the closer dimensions Guide rails allowed.

The object is achieved in that in the aforementioned Door closer a gear is provided with at least a pinion, which is mounted eccentrically and / or on has differently shaped teeth around its circumference. In the case of eccentric bearings, the pinion can be round or have non-circular pitch curves. With the eccentric too in the case of the central mounting of the pinion, the pinion-side Gearing over the circumference of the pinion or over the pitch curve  have differently shaped teeth, for example profile shift, module and / or flank angle can be varied be. The pinion engages in a complementary, the Piston at least one non-positively associated toothing. The Closing torque can be from the closer shaft itself or via a Gear wheel rotatably mounted on the door on the closer axis be transmitted. The same applies to that when opening the Door from the door to the closer shaft or to that on the Closing axle bearing gear to be transmitted opening torque. Both through the eccentric bearing of the pinion as well due to the different design of the teeth Possibility created an optimal course of the total closing torque as well as the opening torque and high efficiency with compact design of the closer.

In preferred versions, in which the pinion is in a complementary Toothing of a piston-fixed rack engages, it is possible that the given Gear teeth on the rack side with a relatively flat pitch curve can be trained.

In one embodiment, the pitch curve goes with the Closer shaft connected eccentrically mounted pinion from an area with a minimal radius in an area of maximum radius over that of the pinion assigned piston-side toothing corresponding to an elongated one and flat S-shaped pitch curve.

Due to the constant engagement between the pinion and piston-side toothing is ensured that all movements in exact synchronization with the Pistons occur and, for example, when striking no problems with a door.

Due to the flat course, d. H. elongated course of the in the basic configuration S-shaped rolling curve of the piston side  Gearing becomes a small pressure angle at the same time possible large gear ratio achieved. The resulting friction losses can be extreme be kept low.

A special compactness, low manufacturing costs and a design that distinguishes high operational safety The invention is characterized in that the piston-side toothing on a rack-shaped Extension of the piston is formed and this extension a wall section of the designed as a hollow piston Piston forms, which in the piston cavity eccentric pinion is located.

With a design that is particularly suitable for floor closers the invention is the closer shaft in one Corner area of the housing arranged and over two eccentric Pinion with the toothing assigned to the piston coupled. This way, at extreme crowded construction very high gear ratios without Losses in terms of functionality and operational safety or achieve lifespan.

According to a further embodiment of the invention, the specifically for the production of those required for swing doors the closing shaft is suitable on both sides via an eccentric pinion with a center symmetrical design Coupled tooth segment, the pivoted and is articulated via a connecting member on the piston, which with respect a middle position corresponding to the closed position is spring-loaded on both sides.

Finally, in a further embodiment of the invention, which is particularly suitable for single action doors that  Closer shaft in turn preferably in a corner area of the Arranged housing and connected with an eccentric pinion, that via an eccentric tooth segment, the swivel axis of which preferably in the opposite of the closer axis Half of the housing is located, as well as a on this tooth segment hinged connecting element connected to the piston, the biased by a spring against a first fixed stop and is movable up to a second fixed stop.

In a special embodiment variant it is provided that the eccentrically mounted pinion with a gear that the Gearbox of a conventional door closer corresponds, interacts. This creates the possibility of being part of a to use conventional closer or a conventional Convert normally open accordingly.

There are special cost advantages in the manufacture of a corresponding embodiment in which it is provided that a conventional door closer with its housing and its inside existing mechanics including gear is used, and that two intermeshing, eccentrically mounted pinions are arranged outside the housing, one of which is on the closer shaft of the conventional door closer and the other on another shaft or axle mounted in the housing is stored to transmit the closing torque to the door. Because the eccentric gear is located outside the housing is, the eccentrically mounted gears can be relatively large and be designed as thinner slices. They can be as cheap Stamped parts are manufactured. Advantageously points the eccentrically mounted pinion is an out-of-round, in particular oval or elliptical pitch curve, but can also be used as round eccentrically mounted pinion.

Particularly preferred versions are also provided, a training z. B. the embodiments described above can represent. They are door closers, who are trained as overhead door closers or floor door closers can be and have a gear with a pinion  differently shaped teeth on its circumference. It is provided that the pinion and / or the Complementary toothing on sections assigned to pinions the pitch curve has differently shaped teeth or have, the design of the teeth in particular depending on the pitch curve sections assigned door opening angles and / or depending on each effective lever arm is varied.

For example, the toothing on the pinion side and / or the complementary toothing assigned to the pinion their pitch curve have a varied profile shift. Advantageously is the profile shift in the pinion side Gearing in a pitch curve section with assigned large door opening angle positive. This means, that the teeth on the pinion shifted radially outwards is. Large door opening angle in the area concerned the pinion's radius is relatively small. The positive Considering the profile shift creates the possibility of the small diameter a closer shaft with a relatively large one Diameter to use for storing the pinion.

In a preferred further development it is provided that the profile shift the toothing on the pinion side in a pitch curve section with assigned small door opening angle negative is trained. In this context, the preferred Complementary piston-side designed as a rack Interlocking corresponding but opposite profile shift like the toothing on the pinion side. This means, that in the area of small opening angles the piston side Gearing has positive profile shift, with the result that the wall in this area by the teeth relative little is reduced and therefore the piston with a small diameter can be executed.  

In further preferred exemplary embodiments, provision is made that the pinion toothing and / or the pinion assigned complementary toothing via the pitch curve Has teeth with different modulus. This means, that teeth of different sizes over the pitch curve sections are provided. This allows the strength of the toothing in the individual pitch curve sections can be set as desired. The module or tooth size is preferably only so chosen large as required for strength.

To approximately the same strength over the entire toothing is provided that the module is inversely proportional is designed to be an effective lever arm.

In special embodiments it is provided that the Gearing in sections of the pitch curve with assigned small door opening angle relatively small module and in sections the rolling curve with an assigned large door opening angle has a larger module. So that is in the area of small opening angle relatively small teeth and in the area of large angle provided larger teeth. This applies to the teeth of the pinion in the same way as for the preferably as Piston rod-shaped toothing on the piston side.

In particularly preferred exemplary embodiments, that the pinion toothing and / or the pinion assigned complementary teeth with at least one tooth has different flank angles. Are preferred several such teeth, especially in the relatively large area Pressure angle provided to reduce wall friction. The pressure angle corresponds to z. B. the pitch angle of the Rack and pinion curve. This configuration of the teeth is of Advantage in the so-called Transition area of the rack, d. H. in Near the turning point of the S-curve and in the complementary toothing on the pinion side. It is a matter of asymmetrical teeth, each with the pressure-side flank a more acute flank angle than a non-pressure flank having. This causes the force component to move towards the  Side wall and thus the wall friction kept relatively low will.

It proves to be particularly advantageous if the design the pinion-side and / or that assigned to the pinion complementary gearing via appropriate setting of Profile shift, module and / or flank angle, in particular is optimized by computer-aided design. The Features profile shift, module and flank angle can Varies over sections of the pitch curve, especially one on the other can be chosen coordinated, but can also can be set constant over the entire rolling curve.

Further advantageous embodiments of the invention are in Subclaims specified.

The invention is described below using exemplary embodiments explained in more detail in connection with the drawing; in the Drawing shows:

Fig. 1 is a schematic diagram for explaining the operation principle of a working eccentric pinion door closer,

Fig. 2 is a schematic representation of an embodiment of an eccentrically mounted pinion,

Fig. 3 is a schematic representation of an embodiment of a pinion gear shown in FIG. 2 associated toothing,

Fig. 4 is a schematic representation of an embodiment of a piston with internal teeth corresponding to FIG. 3 and an associated pinion acc. Fig. 2,

Fig. 5 is a schematic view showing a suitable in particular for floor door closer variant with a high transmission ratio,

Fig. 6 is a schematic partial sectional view of an embodiment of an overhead door closer,

Fig. 7 is a schematic partial sectional view of a formed according to the invention floor door closer for swing doors,

Fig. 8 is a schematic partial sectional view of a formed according to the invention floor door closer for closing doors,

Fig. 9 is a schematic plan view representation of an embodiment that uses a conventional door closer and an additional eccentric and,

Fig. 10 is a schematic side view of the variant according to. Fig. 9.

Fig. 1 shows schematically a toothed pinion 25 to be connected to a closer shaft, which meshes with a piston-fixed toothing 27 .

The piston, not shown, can cooperate in a conventional manner with a closer spring mounted in a housing. Versions as overhead door closers and floor door closers are provided. In the case of an overhead door closer, the pinion 25 or the closer shaft carrying the pinion is connected to a linkage provided for power transmission between the door and the frame. The linkage can preferably be designed as a sliding arm.

The pinion 25 has a pitch curve 26 , which is composed of a first circular section with the radius R ₁, an adjoining circular section with the radius R ₂ and an in turn continuously adjoining circular section with the radius R ₃. The middle pitch curve section with the radius R ₂ has the least curvature, ie the radius is much larger than the radii R ₁ and R ₃.

The rolling curve section with the smallest radius R 3 is in the shown schematic representation in engagement with the toothing 27 , wherein the position shown corresponds to the opening angle 0 of the closer, ie the assigned door is closed. If the door is opened, the spring force of the closer spring acting on the piston and thus on the toothed rack 27 carrying the toothing becomes effective via the lever arm A , ie a high closing force is available in the area of small opening angles.

When the door is opened further or the opening angle is increased, the pinion 25 rotates counterclockwise and the piston-fixed toothing 27 is shifted to the right in the illustration in FIG. 1 against the spring force of the closer spring. The effective lever arm decreases in accordance with the selected course of the rolling curve, down to the value B , which corresponds to the radius R ₁ of the rolling curve 26 of the pinion 25 . In the example shown in FIG. 1, the ratio of A to B is 2 to 1. This ratio corresponds to the translation achieved.

Through a suitable choice of the course of the rolling curve 26 , which does not necessarily have to be composed of circular segments, a very flat course of the rolling curve 28 of the toothing 27 can be achieved, the flat course corresponding to a small pressure angle and thus minimizing the impact on the guide wall the toothing 27 impacting friction component is reached.

The maximum pressure angle in an embodiment corresponding to FIG. 1 is designated by α .

Figs. 2 and 3 show embodiments of a pinion 25 and an associated piston side teeth 27. FIG. 4 shows an exemplary embodiment in which the pinion 25 engages in the toothing 27 , the toothing 27 on the piston side being designed as an internal toothing in a cavity 32 of the piston. The pinion 25 is mounted on the closer shaft, which projects into the cavity 32 .

The pinion 25 has only a portion of its circumference with which it meshes with the piston-side toothing 27 . The toothing of the pinion 25 extends over a pitch curve section from 0 to 180 °.

In the illustration in FIGS. 2 and 3, the pitch curves 26, 27 are drawn into the toothings 25, 27 with a scale which indicates the respective angle of rotation of the pinion 25 or the associated door opening angle of the door for the various engagement positions.

In the embodiment in Fig. 4, the arrangement of the pinion 25 and the associated piston-side toothing 27 and their pitch curves 26, 28 correspond to the scheme according to. Fig. 1.

In the position shown in FIG. 4, there is a rotational position of the pinion 25 of 0 °. The longer lever arm a . The door is closed. When the door is opened, the pinion 25 rotates counterclockwise and, when the door is open, reaches the rotary position of 180 °. In this position, the shorter lever arm b .

The toothing of the pinion 25 and the piston-fixed toothing 27 are designed as involute teeth. This has manufacturing advantages. However, other types of toothing are possible with other designs.

The toothing of the pinion 25 has a profile shift which is designed differently over the circumference of the pinion 25 between 0-180 °. It is negative in the area of small angles, in particular around 0 °, and in the area of large angles, specifically from about 30 ° and increasingly between 80 ° and 180 °. The profile shift increases continuously with the angle of rotation of the pinion 25 from the negative to the positive values.

The piston-side toothing 27 has a corresponding but opposite profile shift. Accordingly, positive values are provided in the area associated with the small door opening angles and negative values in the area with large opening angles.

The positive profile shift present in the toothing of the pinion 25 in the area of large angles enables a closer shaft with a relatively large diameter to be used for mounting the pinion 25 despite the relatively short half-diameter b in this area. On the other hand, the positive profile shift present in the piston-fixed toothing 27 at the assigned small angles ensures that the wall thickness of the piston-side toothing 27 in this area is weakened only relatively little by the toothing, even with a large transmission ratio and steep pressure angle α , that is to say that the wall thickness does not become too thin even with the desired relatively narrow construction. This means that a relatively slim piston can be used even with a large gear ratio.

Furthermore, the toothing of the pinion 25 has different modules varied between 0 and 180 ° over the pitch curve section. The same applies to the piston-fixed toothing 27 .

The module increases continuously with the assigned door opening angle, namely inversely proportional to the respective radius of the pinion 25 or to the respectively effective lever arm. This means that in the area of small door opening angles (around 0 °) with a large lever arm (around a ) a relatively small module, ie small teeth, and in the area of larger angles with a smaller lever arm (around b ) larger module, ie larger teeth are provided .

The associated complementary piston-fixed toothing 27 has a corresponding module variation, in which a relatively small module is provided in the area of small opening angles and a larger module is provided in the area of larger angles.

The module is selected so that the toothing 25, 27 is designed with approximately the same strength in the entire area. Furthermore, in the case of a small module, the rolling process runs particularly smoothly due to the lower flank friction in the case of a small module. The fact that in the area of larger angles a relatively large module but at the same time a positive profile shift is also provided in the pinion 25 , the disadvantageous undercut which otherwise occurs with a large module and a small radius is avoided.

The toothing of the pinion 25 and the piston-fixed toothing 27 also have specially set flank angles, as can be seen in FIGS. 1 to 4, the teeth in particular are designed asymmetrically in the region of the smaller door opening angles by the pressure-side flanks - those in the drawing right flanks 20 of pinion 25 or left flanks 21 of piston-side toothing 27 - steeper, relative to the normal to the pitch curve in the area of the flanks.

This ensures that the force component is heading towards the piston wall is reduced and consequently the wall friction is kept low. This results in good efficiency.

In the exemplary embodiment in FIG. 4, the flanks 20, 21 of the teeth each represent the pressure side, both when opening and when closing. Due to their steeper design, the wall friction is reduced in both opening and closing.

The reduction in friction is particularly when opening important, because friction and spring force act in the same way Direction and against the opening movement; different when closing, there friction and spring force act in opposite directions. Thus, the opening torque to be applied is in each case greater than the closing torque.

The DIN regulations for door closers require that the opening torque is not more than 1.5 times the closing torque may be. This can be done with the configuration according to the invention the flank angle can be easily reached.  

The schematic principle illustration of FIG. 5 shows a suitable particularly for floor spring assembly. In this case, an eccentric pinion 30 is connected to the closer axis, which meshes with a further, rotatably mounted, eccentric pinion 25 , which in turn is in engagement with a toothing 27 which is fixedly connected to the piston, in particular in the form of a rack.

The pitch curve 31 of the eccentric pinion 30 extends with respect to the axis of rotation such that the lever arms effective with respect to the pinion 25 change from the maximum value A ₃ to the minimum value B ₃ over the full opening angle of the closer.

The rolling curve 31 of the pinion 30 is assigned a rolling curve 29 on the pinion 25 , which is indicated by dashed lines and extends approximately over half the circumference of the pinion 25 . The other half of the circumference of the pinion 25 has a rolling curve 26 which interacts with the toothing 27 and which, in turn, is associated with the very flat rolling curve 28 of the toothing 27 .

The minimum effective radius of the pinion 25 is marked with B ₂ and the maximum effective radius with A ₂.

The effective in the interaction of pinion 25 and teeth 27 translations are marked with A ₁ and B ₁.

When using this version, there is a particularly favorable k dimension of, for example, 20 mm, it being essential for the bottom door closer that, despite the very flat rolling curve 28 of the toothing 27, a very high transmission ratio can be achieved. The translation ratio is determined from the product of the individual translations, ie in the present case from the product

For example, a ratio of 4.5  1 is easy to achieve in practice.

It should also be mentioned that the engagement areas of the toothed pinion 25 , ie the areas 26, 29 referred to above as pitch curves, can also overlap. The toothing in FIG. 5 can be designed in a corresponding manner as in FIGS. 2 to 4 with variation of the profile shift, the module and / or the flank angle.

Fig. 6 is a partial sectional view showing a formed according to the invention the upper door closer.

A piston 33 is arranged in the housing 1 and is biased in the usual way into the closed position by means of compression springs 34 . In its area facing away from the springs 34, the piston 33 has a recess or a cavity 32 in which an eccentric pinion 25, which is connected in a rotationally fixed manner to the closer shaft, is arranged. This pinion 25 is in engagement with a toothing 27 which is matched with regard to its rolling curve to the corresponding rolling curve of the pinion 25 . A check valve 43 belonging to the damping device is provided in the area of the piston recess 32 on the spring side.

The position of the piston 33 drawn with solid lines corresponds to the closed position. In this position, the largest lever arm A is effective between the eccentric pinion 35 and the toothing 27 .

If the closer assigned to the wing is pivoted in the opening direction, then the piston 33 moves due to the interaction of pinion 25 and toothing 27 in the position shown in dashed lines, the lever arm becoming smaller and smaller and finally in the position marked with 25 'and 27 ' Pinion and toothing reached the smallest value B.

In this embodiment, the flat course of the toothing 27 must be observed, which ensures that the friction component between the piston 33 and the housing 1 remains minimal.

Fig. 7 shows an embodiment of the invention in the form of a floor closer for swing doors. The eccentric pinion 25 is arranged in a corner region of the housing 1 to achieve the most compact possible construction and is in engagement with a center-symmetrical tooth segment 35 . This toothed segment 35 is articulated in the center and is connected to the piston 33 via a lever 36 . The lever 36 is hinged at both ends.

The piston 33 is provided with a rod 38 which carries an axially adjustable support and guide disk 39 in the region of its end. Between this support and guide plate 39 and a stop sleeve 37 directly adjacent to the piston 33 in the middle position, a compression spring 34 is arranged, which is acted upon depending on the direction of the pivoting movement of the associated swing door, on the one hand via the support and guide plate 39 when supported on the stop sleeve 37 and on the other hand by the stop sleeve 37 when supported on the support and guide disk 39 , which is attached to an adjustable sleeve 40 , which on the one hand slidably receives the piston rod 38 and, on the other hand, can be adjusted in the axial direction from outside the housing can.

By specifically specifying the rolling curves of eccentric pinion 25 and toothed segment 35 , the course of the closing force can in turn be predefined optimally.

Fig. 8 shows an embodiment of the invention in the form of a floor door closer for hinged doors.

In this embodiment, the eccentric pinion 35 is in turn preferably arranged in a corner region of the housing and cooperates with an eccentric segment 41 which is pivotally mounted and is coupled to the piston 33 via a connecting rod 36 . The cup-shaped piston 33 is biased by a spring 34 towards the bottom of the housing 1 and is movable between this bottom and a housing stop 42 .

The eccentricities or rolling curves of the pinion 25 and toothed segment 21 can in turn be selected in accordance with the desired closing force profile.

The variant shown in FIGS. 9 and 10 represents a modification of a conventional door closer according to the invention. A conventional overhead door closer is preferably used. It has a housing 45 with a closer shaft 46 mounted therein and a pinion (not shown) which is mounted centrally on the closer shaft 46 within the housing 45 and which meshes with a piston-fixed toothing in the housing 45 , which is also not shown.

The normally open contact to this extent is equipped with an additional oval gear transmission 47 , which in the exemplary embodiment is designed as an elliptical transmission, in that an eccentrically mounted gear 48 is placed on one end of the closer shaft 46 protruding from the housing 45, which gear wheel 48 with another, likewise on the housing meshes on an additional axis 49 mounted gear 50 . The gear wheel 50 is connected to the linkage, which in the present case is designed as a sliding arm 51 . Alternatively, the axis 49 can also be designed as a shaft connected to the sliding arm 51 , which then represents the closer shaft of the door closer according to the invention.

The gears 48, 50 are designed as elliptical gears. Depending on requirements, they can be dimensioned as relatively thin disks with relatively large half-knives; because they are arranged outside the housing and are therefore not limited by the dimensions of the interior. The gears 48, 50 can therefore be manufactured as cheap stamped parts.

The gear 47 formed with the gears 48, 50 brings the desired translation and ensures a favorable torque curve even when using a sliding arm. Furthermore, the desired construction of the conventional closer is retained.

All embodiments of the invention have in common that a technically simple and economical to implement Construction results, with the eccentric elements as well are inexpensive to manufacture, because for each special Element only once a corresponding broaching tool or a corresponding shape must be manufactured.

The always achievable compactness of the respective closer is in all embodiments paired with an optimal course of the total closing torque, the best possible on the respective Purpose can be adapted.

Claims (26)

1. Door closer with a piston guided in a housing, at least one closer spring cooperating with the piston and a hydraulic damping device and with a closer shaft or closer axis connected to the piston via a transmission, characterized in that the transmission has at least one pinion ( 25, 30, 48 ), which is mounted eccentrically and / or has teeth of different designs on its circumference. 2. Door closer according to claim 1, characterized in that the rolling curve ( 26 ) of the eccentrically mounted toothed pinion ( 25, 50 ) merges continuously from an area with a minimum radius into an area with a maximum radius. 3. Door closer according to claim 1 or 2, characterized in that the complementary piston-side toothing ( 27 ) assigned to the pinion ( 25 ) extends in accordance with an elongated S-shaped rolling curve ( 28 ). 4. Door closer according to claim 3, characterized in that the piston-side toothing ( 27 ) is formed on a rack-shaped extension of the piston ( 33 ) and this extension forms in particular a wall section of the piston designed as a hollow piston, the pinion ( 25 ) in the piston cavity ( 32 ) is arranged. 5. Door closer according to one of claims 1-4, characterized in that the rolling curve ( 26 ) of the eccentrically mounted pinion ( 25 ) consists of several directly merging circular sections, the radii ( R ₁, R ₂, R ₃) different and their Centers are offset from each other. 6. Door closer according to claim 5, characterized in that a second, a substantially larger radius ( R ₂) having, the first rolling curve section continuously continuing second rolling curve section follows a first, the large opening angles of the closer, and that this second Rolling curve section continuously connects a third rolling curve section, the radius ( R ₃) of which is smaller than the radius ( R ₁) of the first rolling curve section and which is assigned to the area of the door closer with a smaller opening angle. 7. Door closer according to one of claims 1 to 6, characterized in that the closer shaft is arranged in a corner region of the housing ( 1 ) and is coupled via two eccentric pinions ( 25, 30 ) with the toothing ( 27 ) assigned to the piston, the toothed pinion ( 25 ) engaging with the piston-side toothing ( 27 ) has a first eccentric rolling curve ( 26 ) assigned to the piston-side toothing ( 27 ) and a second eccentric rolling curve ( 29 ) assigned to the toothed pinion ( 30 ) connected to the closer shaft. 8. Door closer according to one of claims 1 to 7, characterized in that the closer shaft is arranged in a corner region of the housing ( 1 ) and coupled to generate the double-sided closing movement required for swing doors via an eccentric pinion ( 25 ) with a centrally symmetrical toothed segment ( 35 ) which is pivotally mounted and is articulated via a connecting element ( 36 ) on the piston ( 33 ) which is spring-biased on both sides with respect to a central position corresponding to the closed position. 9. Door closer according to one of claims 1 to 8, characterized in that the closer shaft is arranged in a corner region of the housing ( 1 ) and is connected to an eccentric pinion ( 25 ) via an eccentric toothed segment ( 41 ), the pivot axis of which is in which is located opposite the closer shaft, and is connected to the piston ( 33 ) via a connecting element ( 36 ) articulated on this toothed segment ( 41 ), which is biased by a spring against a first fixed stop to form a closer for stop doors and up to a second Fixed stop ( 42 ) is movable. 10. Door closer according to one or more of the preceding claims, in particular claims 1 to 6, characterized in that the eccentrically mounted pinion ( 47, 48, 50 ) cooperates with a gear which corresponds to the gear of a conventional door closer ( 45 ). 11. Door closer according to claim 10, characterized in that a conventional door closer is used with its housing ( 45 ) and its mechanism therein including the gear; and that two intermeshing eccentrically mounted pinions ( 48, 50 ) are arranged outside the housing ( 45 ), one of which ( 48 ) on the closer shaft ( 46 ) of the conventional door closer and the other ( 50 ) on another in the housing ( 45 ) mounted, shaft or axis ( 49 ) is mounted, which now forms the closer shaft or closer axis. 12. Door closer according to one or more of the preceding claims, characterized in that the toothed pinion ( 25, 30, 48 ) and / or the complementary toothing ( 27, 50 ) assigned to the toothed pinion on sections of the rolling curve ( 26, 28 ) are configured differently Has or have teeth, the configuration of the teeth being varied in particular as a function of the door opening angles associated with the rolling curve sections ( 26, 28 ) and / or as a function of the respectively effective lever arm. 13. Door closer according to claim 12, characterized in that the pinion-side toothing ( 25 ) and / or the complementary toothing ( 27 ) assigned to the pinion has a profile shift which varies over its rolling curve. 14. Door closer according to claim 13, characterized in that the profile shift of the toothed pinion-side toothing ( 25 ) in a pitch curve section ( 26 ) with an associated small opening angle is designed to be negative. 15. Door closer according to claim 13 or 14, characterized in that the profile shift of the toothed-tooth-side toothing ( 25 ) in a pitch curve section ( 26 ) with an associated large door opening angle is positive. 16. Door closer according to one of claims 13 to 15, characterized in that the profile shift in the pinion-side toothing ( 25 ) increases continuously with increasing door opening angle in the direction of positive profile shift. 17. Door closer according to one of claims 13 to 16, characterized in that the complementary toothing ( 27 ) assigned to the pinion ( 25 ) has a corresponding but opposite profile shift as the toothing-side toothing. 18. A door closer characterized to 17 according to any one of claims 12, that the pinion toothing (25) and / or the pinion (25) associated with complementary toothing (27) about their pitch curve (26, 28) has teeth with different modulus. 19. Door closer according to claim 18, characterized in that the module is designed inversely proportional to the effective lever arm ( A, B; a, b) of the pinion ( 25 ). 20. Door closer according to claim 18 to 19, characterized in that the toothing ( 25, 27 ) in sections of the rolling curve ( 26, 28 ) with an associated small door opening angle relatively small module and in sections of the rolling curve ( 26, 28 ) with an associated large door opening angle has a larger module. 21. Door closer according to claim 20, characterized in that the module with the assigned door opening angle increases continuously. 22. A door closer according to any one of claims 18 to 21, characterized in that the (25) associated with complementary toothing (27) corresponding to the toothed pinion varied module as the pinion toothing (25). 23. A door closer according to any one of claims 12 to 22, characterized in that the pinion toothing (25, 20) and / or the pinion (25) associated with complementary toothing (27, 21) has at least one asymmetrically constructed tooth with different flank angles. 24. A door closer according to claim 23, characterized in that in particular in a pitch curve section ( 26, 28 ) associated with a small door opening angle , the pressure-side flank ( 20, 21 ) of the tooth has a more acute flank angle than the non-pressure-side flank of the same tooth. 25. Door closer according to claim 23 or 24, characterized in that the complementary toothing ( 25 , 21 ) assigned to the pinion ( 25 ) has corresponding flank angles as the toothing-side toothing ( 25, 20 ). 26. Door closer according to one or more of the preceding claims, characterized in that the configuration of the pinion-side toothing ( 25, 30, 48 ) and / or the complementary toothing ( 27, 50 ) assigned to the pinion by appropriate setting of profile shift, module and / or flank angle, in particular optimized by computer-aided design.