Abstract:
A filter ( 18 ) is fastened by means of a releasable detent connection ( 20 ) in a fastening housing part ( 14 ). One detent component ( 32 ) is connected to the filter element ( 18 ) and one detent component ( 36 ) is connected to the fastening housing part ( 14 ). At least one detent means ( 32 ) of one of the detent components engages in a bayonet-like manner in a cut-out ( 38 ) in the other detent component ( 36 ). One switching component ( 60 ) of a switching device ( 58 ) is connected to the filter element ( 18 ) and one switching component ( 62 ) is connected to the fastening housing part ( 14 ). One of the switching components ( 60 ) includes at least one switching lug ( 76 ) extending radially to a rotational/plug-in axis ( 30 ) of the filter ( 10 ), and one of the switching components ( 62 ) includes a switching slot ( 78 ) for guiding the switching lug ( 76 ). The switching slot ( 78 ) guides the switching lug ( 76 ) and thereby effects a rotational movement of the filter element ( 18 ) relative to the fastening housing part ( 14  to move the detent means ( 32 ) out of an insertion/withdrawal region ( 46 ) into a closing region ( 40 ) of the cut-out ( 38 ), or out of a retaining region ( 42 ) into the insertion/withdrawal region ( 46 ).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a US Bypass Continuation of International Application PCT/EP2011/057908 filed May 17, 2011. This application claims the benefit under 35 USC 119 of German patent application DE 10 2010 020 727.6 filed in Germany on May 17, 2010. International Application PCT/EP2011/057908 is hereby incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention concerns a filter for filtering fluids, in particular fuel or oil, in particular of a motor vehicle, including a housing which is comprised of at least two housing parts, and a filter element which is attached by means of a releasable detent connection in one of the housing parts and acts as a fastening housing part for the filter element, wherein the detent connection includes at least two interacting detent components, and one of the detent components is connected with the filter element and one of the detent components with the fastening housing part. 
       BACKGROUND OF THE INVENTION 
       [0003]    EP 0 959 978 B1 discloses a filter which includes a housing which, in turn, is comprised of two screwed-together housing parts. For producing a reliable detent connection between filter element and a cover housing part, a recess is provided in the area of the cover housing part. This recess has different functional areas, namely a locking area, a retaining area, a translation area and an insertion/removal area which are necessary for effecting or for releasing the detent connection. Detent means of the filter element can be moved between the functional areas by relative rotations between the filter element and the cover housing part. 
         [0000]    There remains a need in the art for a filter element, a fastening housing part, and a releasable detent connection configured in such a way that the filter element can be inserted into and removed from the filter housing in an easier and more reliable way and further, when exchanging the filter element, no fluid from the filter should reach uncontrollably the surroundings, if possible. 
       SUMMARY OF THE INVENTION 
       [0004]    An object of the present invention is to provide a filter for filtering fluids, in particular fuel or oil, in particular of a motor vehicle, including a housing which is includes of at least two housing parts, and a filter element which is attached by means of a releasable detent connection in one of the housing parts and acts as a fastening housing part for the filter element, wherein the detent connection includes at least two interacting detent components, and one of the detent components is connected with the filter element and one of the detent components with the fastening housing part and at least one of the detent components includes at least one detent means and one of the detent components a recess matching the detent means, in which recess the detent means hooks in a bayonet-like manner, and wherein the recess may include at least one or more of the following limitations:
       a locking area for receiving the detent means while the housing parts are connected,   a retaining area for receiving the detent means during opening of the filter housing,   a translation area for releasing the detent means in the recess, and   an insertion/removal area for resistance-free joining and separating the detent means and the recess.       
 
         [0009]    Another object of the invention is to provide a filter element of a filter which includes a detent component that is adapted to form with a detent component, which is connected with a fastening housing part of a filter housing, a releasable detent connection, wherein one of the detent components includes at least one detent means and one of the detent components a recess matching the detent means, in which recess the detent means is hooked in a bayonet-like manner. 
         [0010]    A further object of the invention is to present a fastening housing part of a filter housing of a filter which includes a detent component, this is adapted to form with a detent component, which is connected with a filter element of the filter, a releasable detent connection, wherein at least one of the detent components includes at least one detent means and one of the detent components a recess matching the detent means, in which recess the detent means is hooked in a bayonet-like manner. 
         [0011]    Additionally, objects of the invention concern a telescopic switching element of a switching device of a releasable detent connection for attachment of a filter element in a fastening housing part of a filter for filtering fluids, in particular fuel or oil, in particular of a motor vehicle. 
         [0012]    The above objects are solved according to the invention in that a switching device includes at least two corresponding switching components and one of the switching components is connected with the filter element and one of the switching components with the fastening housing part, and one of the switching components includes at least one switching lug that extends radially relative to a rotation/insertion axis of the filter and one of the switching components includes a switching guide for guiding the switching lug, so that the switching guide leads the switching lug upon an impulse-like relative axial movement of the filter element in a direction toward the fastening housing part and thereby effects a rotation of the filter element relative to the fastening housing part around the rotation/insertion axis for moving the detent means from the insertion/removal area into the locking area or from the retaining area into the insertion/removal area, depending on the position of the detent means in the recess before the axial movement is effected. 
         [0013]    According to the invention, the detent connection is activated and deactivated with the switching device. For this purpose, an impulse-like axial movement of the filter element relative to the fastening housing part is converted into a relative rotation for moving the detent means in the areas of the recess. Such impulse-like axial movements can be generated preferably, with the filter housing being open, simply with one hand by hitting with the free end face of the filter element against a solid body, in particular a tabletop or a drain pan, without this requiring that the possibly fluid-contaminated filter element be directly touched. For assembling the filter, the filter element is inserted into the filter housing part. The switching lug is rotated with the switching device by a first impulse-like axial movement of the filter element from the insertion/removal area into the locking area. The filter element is thus secured in the fastening housing part, even when the latter is pointing with its open side in downward direction. The fastening housing part with the filter element can thus be mounted in a simple and reliable way even at sites that are difficult to access, especially hidden sites, in an engine compartment, on an appropriate system-mounted housing part. For dismantling, the fastening housing part with the filter element is separated from the system-mounted housing part. When doing so, the detent means is rotated across the translation area automatically into the retaining area of the recess so that the filter element is retained in the fastening housing part. The fastening housing part can then be separated safely, without the filter element falling out, with one hand from the system-mounted housing part and, with the opening pointing in downward direction, can be put down to allow the residual fluid still contained in the fastening housing part to drain. Because the detent means are still locked within the retaining area, the filter element cannot fall out uncontrollably when carrying out a one-handed turning of the fastening housing part. For separating, another impulse-like axial movement is exerted on the filter element by means of which, with the aid of the switching device, the detent means is rotated from the retaining area into the insertion/removal area. Then the filter element is separated without resistance from the fastening housing part. The switching device can be located advantageously at the center of an end face of the filter element in order to save space. The detent device can be simply arranged on the circumferential side on the same or the other end face of the filter element. In reverse, the switching device can be also arranged on the circumferential side of one of the end faces and the detent device at the center of one of the end faces of the filter element. The detent means, in particular in the form of a detent lug, can be advantageously connected directly or by means of a detent ring or a similar connecting part on the filter element. The recess can be realized at an elevated part on the inner wall side of the fastening housing part. In this manner, the detent means, which is more susceptible to wear than the recesses, can be exchanged together with the filter element. The switching lug can be realized on a separate component, in particular a stationary cylinder or a dipping cylinder of a telescopic switching element. This component can be fastened releasably, in particular with a screw connection, to the fastening housing part so that it can be simply exchanged, in particular in case of wear. The component can thus be retrofitted also in existing fastening housing parts. The component can be prefabricated as a module and thus be mounted easily. The switching guide can be simply realized in particular in an axial recess of an end disc of the filter element. Since the detent connection and the switching device are matched to each other, it is prevented that a filter element can be mounted without a detent connection that is not matched to the fastening housing part or with a faulty detent connection and/or switching device. In this manner, interferences with the filter function, caused in particular by wrong assembly, are prevented. 
         [0014]    Advantageously, the switching guide may be realized as a switching sleeve, which includes a succession of progressing switching teeth or angled guide members in circumferential direction. A switching sleeve with progressing switching teeth or angled guide members can be simply produced. In particular such switching guide can be simply shaped from plastic or cut, milled or punched from metal. 
         [0015]    In another advantageous aspect of the invention, the switching device may comprise at least one elastic element, in particular a spiral compression spring, for realizing a pre-tension between the fastening housing part and the filter element. A restoring force, in particular a spring force, can thus be generated between the fastening housing part and the filter element. For connecting the fastening housing part with the other housing part, the filter element can be pushed against the elastic element into the fastening housing part in axial direction. The thus generated restoring force causes when changing, in particular releasing, the detent connection, such that the filter element is pressed in axial direction out of the fastening housing part. The filter element in this way releases in the fastening housing part a volume into which the residual fluid which has remained in the filter element can flow in. In this manner it is prevented that fluid reaches the surroundings when exchanging the filter element. The elastic element is matched to the filter element and the fastening housing part, so that an installation of the filter element is not possible without the matching elastic element. In this manner, malfunctions of the filter are prevented. 
         [0016]    One of the switching components may advantageously comprise a telescopic switching element with a stationary cylinder and a dipping cylinder between which the elastic element is acting and which are inserted into each other, with generation of a pre-tension of the elastic element, for inserting the filter element into the fastening housing part. In a telescopic switching element, the stationary cylinder and the dipping cylinder are guided stably relatively to each other when carrying out axial movements. 
         [0017]    Further, the telescopic switching element may comprise advantageously a releasable locking mechanism which is activated in the basic state and blocks pushing together the telescopic switching element, and the other switching component can comprise at least one release element which is matched to the locking mechanism such that the release element deactivates the locking mechanism when joining the telescopic switching element and the other switching component. The release element and the locking mechanism interact according to the lock-and-key principle wherein one of the components is connected with the filter element and the other component with the fastening housing part. To release the locking mechanism, the matching release element is necessary; otherwise, the extended telescopic switching element prevents that the filter element can be inserted completely into the fastening housing part. Then the filter element projects from the fastening housing part and this can be easily recognized from outside. In this manner, it is prevented that a filter element is employed that does not ting the filter. 
         [0018]    In another advantageous aspect of the invention, a ring seal may be fastened in particular to an end face of the filter element for sealing relative to the filter housing and is adjustable axially, with respect to the rotation/insertion axis relative to the filter element. The ring seal may have advantageously a half moon-shaped profile so that the ring seal is curved on the radial exterior side and can optimally rest tightly against an appropriate sealing surface of the filter housing. In radial direction inwardly, the ring seal may be flat and, in order to save space, can rest against a suitable support ring which may carry and support the ring seal. The support ring may be connected with a simple guide mechanism to the filter element so as to be slideable relative thereto in axial direction. By means of the slideable ring seal the filter element on this end face is supported floatingly in the filter housing. The ring seal can be moved advantageously in particular at the time of opening and closing the filter housing. The ring seal can be simply exchanged together with the filter element. Advantageously, the slideable ring seal can be arranged at the end face that is facing away from the bottom of the fastening housing part outside of the fastening housing part and seal relative to the inside of the other, preferably system-mounted, housing part. When separating the fastening housing part from the other housing part, the ring seal can still seal up to the point of reaching its movement limit relative to the other housing part in order to prevent that fluid from the other housing part reaches the surroundings. When the ring seal is so designed that it seals relative to the other housing part, the wall thickness of the fastening housing part can be reduced advantageously. Moreover, by means of the moveable ring seal it can be prevented that a faulty ring seal or a ring seal that does not fit the filter housing or a filter element with a faulty or non-fitting ring seal is used so that disturbances of the filter function can be prevented in a simple way. 
         [0019]    In the present invention, the technical object is solved according to the invention further in that the filter element includes a switching component that is adapted to interact with a switching component of the fastening housing part in such a way that a switching device embodied with the switching components, upon an impulse-like relative axial movement of the filter element in a direction toward the fastening housing part, causes a rotation of the filter element relative to the fastening housing part around the rotation/insertion axis of the filter in order to move the detent means in the recess, depending on the position of the detent means in the recess before effecting the axial movement. The advantages enumerated above in connection with the filter according to the invention extend likewise to the filter element. 
         [0020]    In an advantageous aspect of the invention, a ring seal may be provided at an end face of the filter element for sealing relative to the filter housing, wherein the ring seal is slideable axially relative to the filter element. In this manner, the filter element can be supported floatingly in the filter housing. Further, the assembly and disassembly can be facilitated; in particular escape of fluid into the surroundings is prevented when dismantling. The ring seal can be exchanged simply together with the filter element. 
         [0021]    The filter element may include advantageously at least one release element that is suited to deactivate a releasable locking mechanism of a telescopic switching element of the switching device upon installation of the filter element into the fastening housing part. The advantages mentioned above in connection with the release element of the filter according to the invention extend likewise to the filter element. 
         [0022]    For the rest, the technical object is solved according to the invention in that the fastening housing part includes a switching component that is suited to interact with a switching component of the filter element such that a switching device embodied with the switching components, upon an impulse-like relative axial movement of the filter element in a direction toward the fastening housing part, causes a rotation of the filter element relative to the fastening housing part around a rotation/insertion axis of the filter in order to move the detent means into the recess, depending on the position of the detent means in the recess prior to effecting the axial movement. The advantages mentioned above in connection with the filter and filter element according to the invention extend likewise to the filter element. 
         [0023]    Moreover, the technical object is solved according to the invention in that the telescopic switching element is adapted to be connected with the filter element or with the fastening housing part and the telescopic switching element includes at least one switching lug that extends radially relative to a rotation/insertion axis of the filter, the switching lug adapted to be guided in a switching guide that is connected appropriately with the fastening housing part or with the filter element in such a way that the switching guide guides the switching lug upon an impulse-like relative axial movement of the filter element in a direction toward the fastening housing part and thereby causes a rotation of the filter element relative to the fastening housing part around the rotation/insertion axis for actuation of the detent connection. The advantages mentioned above in connection with the filter, filter element and fastening housing part according to the invention extend likewise to the filter element. 
         [0024]    Advantageously, the telescopic switching element may comprise a releasable locking mechanism which is activated in the basic state and blocks the telescopic switching element from being pushed together, and which is matched to a release element that is connected to the fastening housing part or to the filter element such that the release element, upon installation of the filter element into the fastening housing part, deactivates the locking mechanism. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The accompanying Figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention. 
           [0026]    Features of the present invention, which are believed to be novel, are set forth in the drawings and more particularly in the appended claims. The invention, together with the further objects and advantages thereof, may be best understood with reference to the following description, taken in conjunction with the accompanying drawings. The drawings show a form of the invention that is presently preferred; however, the invention is not limited to the precise arrangement shown in the drawings. 
           [0027]      FIG. 1  schematically depicts a longitudinal section of an oil filter with an exchangeable filter element which is fastened with a releasable detent connection in a filter cup, wherein the detent connection is activatable and deactivatable with a switching device; 
           [0028]      FIG. 2  schematically depicts an exploded view of the detent connection and of the switching device of the oil filter of  FIG. 1  wherein from bottom to top a side view of a dipping cylinder, a developed view of the geometry of a switching sleeve of the switching device, a developed view of the geometry of a detent guide, and a longitudinal section of a detent end disc of the filter element with three detent lugs are shown; 
           [0029]      FIG. 3  is an isometric detail view of the detent end disc of the filter element of  FIG. 2 ; 
           [0030]      FIG. 4  is an isometric detail view of the filter element of  FIGS. 1 to 3 , cut in half in longitudinal direction, in the area of a seal end disc with a moveable ring seal; 
           [0031]      FIG. 5  is an isometric representation of another aspect of a filter element according to the invention present in the filter element of  FIG. 1 ; 
           [0032]      FIG. 6  is an isometric representation of the filter element of  FIG. 5 , cut in half in longitudinal direction, in the area of a detent end disc; 
           [0033]      FIG. 7  schematically depicts a longitudinal section of an oil filter with the filter element according to the inventive aspects presented in  FIGS. 5 and 6  in the area of the detent connection and the switching device; 
           [0034]      FIG. 8  schematically depicts an isometric representation of a dipping cylinder of the oil filter of  FIG. 7 ; 
           [0035]      FIG. 9  schematically depicts an isometric representation of a another aspect of the invention with a filter element which is similar to the filter elements of  FIGS. 1 to 7 ; 
           [0036]      FIG. 10  schematically depicts an isometric representation of further aspect of the invention having a filter element which is similar to the filter elements of  FIGS. 1 to 7  and  9 ; 
           [0037]      FIG. 11  schematically depicts a longitudinal section of an oil filter that is similar to the oil filters of Figure and  1  and  7  with a moveable ring seal in the area of the screw connection of a housing cup with a housing cup; 
           [0038]      FIG. 12  schematically depicts the ring seal of  FIG. 11  in cross-section; 
           [0039]      FIG. 13  schematically depicts a detail of an alternative detent guide which is similar to the detent guide of  FIG. 2 ; 
           [0040]      FIG. 14  schematically depicts an isometric representation of the filter cup with the filter element of the oil filter of  FIG. 1  in an assembly state before connecting with the filter head; 
           [0041]      FIG. 15  schematically depicts an isometric representation of the filter cup with the filter element of  FIGS. 1 and 14  in a dismantled state for draining off the residual oil; 
           [0042]      FIG. 16  schematically depicts a longitudinal section of an oil filter with a filter element according to a fifth embodiment which is similar to the oil filter of  FIGS. 7 and 8  in the area of a detent connection and a switching device in a first assembly state; 
           [0043]      FIG. 17  schematically depicts the oil filter of  FIG. 16  in the final assembled state; 
           [0044]      FIG. 18  schematically depicts the oil filter of  FIG. 16  in the first assembly state in a part-sectional view; 
           [0045]      FIG. 19  schematically depicts the oil filter of  FIG. 17  in the final assembled state in a part-sectional view; 
           [0046]      FIG. 20  schematically depicts the oil filter of  FIG. 18  in the first assembly state without illustration of the filter element; 
           [0047]      FIG. 21  schematically depicts the oil filter of  FIG. 19  in the final assembled state without illustration of the filter element; 
           [0048]      FIG. 22  is a detail view of the switching device of the oil filter of  FIG. 16  in the first assembly state; 
           [0049]      FIG. 23  is a detail view of the switching device of the oil filter of  FIG. 17  in the final assembled state; 
           [0050]      FIG. 24  is a detail view of the filter element of the oil filter of  FIG. 16 ; 
           [0051]      FIG. 25  depicts a stationary cylinder of a telescopic switching element of the switching device of the oil filter of  FIG. 16 ; 
           [0052]      FIG. 26  depicts a dipping cylinder of the telescopic switching element of the switching device of the oil filter of  FIG. 16  viewed in the direction of the inside; and 
           [0053]      FIG. 27  depicts the dipping cylinder of  FIG. 27  with a view of the outside. 
       
    
    
       [0054]    In the Figures above, same components are provided with the same reference characters. 
         [0055]    Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. 
       DETAILED DESCRIPTION 
       [0056]    In  FIG. 1  an oil filter  10  is shown for filtering engine oil of an internal combustion engine, not shown here, of a motor vehicle. 
         [0057]    The oil filter  10  has a filter housing  12  which is composed of a filter cup  14  and a filter head  16 . The filter head  16  is connected in a way of no further interest in this context to an engine oil system, not shown, of the internal combustion engine. The filter cup  14  is screwed from below into the filter head  16  and is suspended from it. 
         [0058]    An interchangeable filter element  18  is fastened by means of a releasable detent connection  20  in the filter cup  14  that functions as a fastening housing part. The filter element  18  includes a filter medium  22  which is folded coaxially relative to a rotation/insertion axis  30  of the filter housing  12  in a zigzag shape. A seal end disc  24  and a detent end disc  26  are fastened to the end faces of the filter medium  22 . In the interior of the filter medium  22  a support tube  28  that is fluid-permeable in radial direction extends between the seal end disc  24  and the detent end disc  26  coaxially to the rotation/insertion axis  30 . 
         [0059]    The rotation/insertion axis  30  is the axis relative to which during assembly or disassembly of the oil filter  10  the rotary and insertion movements of the filter head  16 , the filter cup  14  and the filter element  18  relatively to each other occur. The term rotation/insertion axis  30  is used in the following for better clarity also for the individual components of the oil filter  10  with open filter housing  12  and is referenced in the Figures accordingly. In these cases, this refers to the respective axis of the component in question which coincides for the mounted oil filter  10  with the rotation/insertion axis  30  of the filter housing  12 . The concepts “radial”, “axial” and “in circumferential direction” refer to the rotation/insertion axis  30  or the corresponding axis of the respective component. 
         [0060]    The detent connection  20  includes three detent lugs  32  as detent means which, as shown in particular in  FIG. 3 , are arranged evenly distributed on the circumferential side of the detent end disc  26  of the filter element  18  that is facing the bottom  34  of the filter cup  14 . The detent lugs  32  extend in radial direction outwardly. The detent lugs  32  interact with a detent guide  36  of the detent connection  20 . 
         [0061]    The detent guide  36  is located near the bottom  34  on the radial inner circumferential side of the filter cup  14 . The detent guide  36  includes an elevated part  37  extending in radial direction with three recesses  38  that in each case correspond with one of the detent lugs  32 . In the recesses  38  the detent lugs  32  can lock in a bayonet-like manner. In  FIG. 1 , the area of the detent guide  36 , which is hidden actually by the filter element  18 , is indicated in dashed lines to improve comprehension. The recesses  38  comprise, as shown in particular in  FIG. 2 , in each case a locking area  40 , a retaining area  42 , a translation area  44  and an insertion/removal area  46 . 
         [0062]    The insertion/removal area  46  extends in axial direction. At its end that is facing the open side of the filter cup  14  the insertion/removal area  46  includes an opening  48 . The opening  48  is formed all together approximately in a funnel shape. The edges are rounded, so that insertion of the detent lugs  32  is simplified. At its closed end, the insertion/removal area  46  passes into the locking area  40 . 
         [0063]    The locking area  40  extends in circumferential direction on the rearward side of the insertion/removal area  46  relative to a rotational direction of locking of the filter cup  14 . The rotational direction of locking is indicated in  FIG. 2  by arrow  50 . 
         [0064]    The retaining area  42  is located in axial direction between the opening  48  of the insertion/removal area  46  and the locking area  40 . It extends in circumferential direction at the front side of the insertion/removal area  46  relative to the rotational direction of locking  50  of the filter cup  14 . A retaining side  52  of the retaining area  42  facing the opening  48  extends in a plane perpendicular to the rotation/insertion axis  30 . An opposite guiding side  54  extends at an angle toward the retaining side  52  so that the retaining area  42  as a whole has an approximately triangular shape. Between the insertion/removal area  46  and the retaining area  42  a triangular projection  56  borders the guiding side  54  and tapers in axial direction away from the bottom  34 . The projection  56  forms a surmountable stop for the detent lug  32 . The projection  56  prevents that the filter element  18  is turned in the filter cup  14  unintentionally such that the detent lug  32  reaches the insertion/removal areas  46  causing the detent connection  20  to be released. 
         [0065]    The axial distance between the retaining side  52  of the retaining area  42  and a locked position retaining side  57  on the side of the locking area  40  that is facing the opening  48  determines how far the filter element  18  projects in a secured position described below from the filter head  14 . 
         [0066]    The translation area  44  forms the closed end of the insertion/removal area  46 . It extends at an angle to the rotation/insertion axis  30  of the filter cup  14  of the locked position retaining side  57  of the locking areas  40  to the projection  56  of the retaining area  42 . The contour of the translation area  44  passes into the contour of the projection  56 . 
         [0067]    A switching device  58  includes a telescopic switching element  60  at the filter head  14  which corresponds with a switching sleeve  62  on the filter element  18 . 
         [0068]    The telescopic switching element  60  includes a hollow stationary cylinder  64  which is open at an end face and is closed at the other end face. The stationary cylinder  64  is fastened with a screw  68  at the closed end face in a depression  66  of the bottom  34  of the filter cup  14 . 
         [0069]    In the stationary cylinder  64  a coaxial dipping cylinder  70  is moveable axially relative to the rotation/insertion axis  30 . The dipping cylinder  70  is also hollow and closed at one end face. The open end face of the dipping cylinder  70  is facing the closed end face of the stationary cylinder  64 . 
         [0070]    The dipping cylinder  70  includes at its open end face two spring hooks  72  which extend in axial direction and whose locking sides are directed in radial direction outwardly. The spring hooks  72  are guided in two suitable guide slots  74  in the circumferential side of the stationary cylinder  64 . The guide slots  74  extend axially relative to the rotation/insertion axis  30 . The guide slots  74  are closed relative to both end faces of the stationary cylinder  64 . The dipping cylinder  70  is secured against rotation by means of the spring hooks  72  and is axially slideable in the stationary cylinder  64 . 
         [0071]    The dipping cylinder  70  includes two switching lugs  76  which are arranged on the radial external circumferential side and extend in radial direction outwardly. The switching lugs  76  are arranged near the closed end face of the dipping cylinder  70  on sides that are diametrically opposed relative to the rotation/insertion axis  30 . 
         [0072]    The switching sleeve  62  is a cylindrical depression which extends in the center of the detent end disc  26  of the filter element  18  in axial direction toward the seal end disc  24 . The switching sleeve  62  includes at its radial inward side a switching guide  78  that projects in radial direction inwardly. The switching guide  78  includes a succession of progressing switching teeth  80  in circumferential direction. In  FIG. 1  the area of the switching guide  78 , which is actually hidden in that representation by the dipping cylinder  70 , is shown in dash-dotted lines for better comprehension. Each progressing switching tooth  80  has, as shown in particular in  FIG. 2 , a surface extending in axial direction and a guide surface  82  extending at an angle thereto. The guide surfaces  82  are arranged on the side of the switching guide  78  that is facing the opening of the switching sleeve  62 . The switching guide  78  serves for guiding the switching lugs  76  in case of an impulse-like relative axial movement of the filter element  18  into the filter cup  14 . 
         [0073]    Inside the telescopic switching element  60  a spiral compression spring  84  is arranged coaxially to the rotation/insertion axis  30 . The spiral compression spring  84  is supported with one end on an end wall of the stationary cylinder  64  and with the other end on an end wall of the dipping cylinder  70 . The spiral compression spring  84  of the telescopic switching element  60  serves for introducing a spring force that is acting axially to the rotation/insertion axis  30  for pressing the switching lugs  76  against the switching guide  78 . 
         [0074]    On the seal end disc  24  of the filter element  18 , as shown in the  FIGS. 1 and 4 , a flexible ring seal  86  for sealing relative to the filter housing  12  is arranged. The ring seal  86  is fastened coaxially to the rotation/insertion axis  30  on a shape-stable support ring  88  which is slideable, in turn, axially relative to the filter element  18 . The ring seal  86  has a half moon-shaped profile whose curved side is positioned in radial direction outwardly. The straight axial inner side of the ring seal  86  rests flat against a radial outwardly positioned circumferential side of the support ring  88 . In the radial outwardly positioned circumferential side of the support ring  88  there is a circumferential groove  90  engaged by a suitable projection  92  that is provided for holding the ring seal  86  on the support ring  88  and is located on the radial inner side of the ring seal  86 . 
         [0075]    On an end face of the support ring  88  which is facing the filter element  18  a plurality of guide frames  94  are arranged in circumferential distribution. The guide frames  94  each have an elongate guide gap  96  which extends in axial direction. The guide frames  94  taper at their free ends in order to facilitate assembly. 
         [0076]    On the radial outer circumferential side of the seal end disc  24  there are guide projections  98  which correspond with the guide gaps  96 . The guide projections  98  extend radially in outward direction. The guide frames  94  are guided on the guide projections  98 . 
         [0077]    The expansion of the guide projections  98  in circumferential direction corresponds approximately to the expansion of the guide gaps  96  in circumferential direction so that a relative movement between the support ring  88  and the seal end disc  24  relative to the rotation/insertion axis  30  is prevented. 
         [0078]    The expansion of the guide gap  96  in axial direction is significantly bigger than the expansion of the guide projections  98  in axial direction so that a relative movement of the support ring  88  with the ring seal  86  is possible in axial direction relative to the filter element  18 . 
         [0079]    For assembly of the oil filter  10 , the filter element  18  with the detent end disc  26  leading is inserted axially relative to the rotation/insertion axis  30  into the filter cup  14 . In this context, it may possibly be necessary to turn the filter element  18  in the filter cup  14  somewhat around the rotation/insertion axis  30  so that the three detent lugs  32  are able to glide unhindered in each case into one of the insertion/removal areas  46  of the detent guide  36 . This is facilitated by the funnel-shaped openings  48  with the rounded edges. Upon insertion of the filter element  18 , the dipping cylinder  70  dips into the switching sleeve  62 . The spiral compression spring  84  ensures that the filter element  18  is not immersed completely into the filter cup  14 . The filter element  18  projects from the filter cup  14  in this phase of assembly. The support ring  88  with the ring seal  86  is outside of the filter cup  14 . 
         [0080]    By means of the geometrically matched pairs of the detent lugs  32  with the recesses  38  of the detent guide  14  and the pairing of the switching lugs  76  of the dipping cylinder  70  with the switching guide  78  of the switching sleeve  62 , it is prevented that the filter element  18  can be mounted wrongly or that a non-matching filter element can be used. In this manner, the risk that malfunctions of the oil filter  10  occur is reduced. 
         [0081]    The filter element  18  is pressed for activation of the detent connection  20  with an impulse-like movement in axial direction into the filter cup  14  in. In this context, the movement direction of the switching guide  78  is indicated in  FIG. 2  with arrow  99 . This axial movement can be generated by pressing with one hand or by pressing the filter cup  14  with the free end face of the filter element  18  against a tabletop or another stable object. With the axial movement the switching lugs  76  of the dipping cylinder  70  are guided along the guide surfaces  82  of the switching guide  78  so that a rotation of the filter element  18  is caused relatively to the filter cup  14  around the rotation/insertion axis  30 . In this context, the rotation direction of the filter element  18  is indicated in  FIG. 2  by arrows  100 . The detent lugs  32  are moved from the insertion/removal areas  46  of the respective recess  38  into the locking areas  40  by the rotation of the filter element  18 . 
         [0082]    The locking areas  40  serve for receiving the detent lugs  32  when screw-connecting the filter cup  14  with the filter head  16 . In this dismantling phase the filter element  18  presses against the spiral compression spring  84  so that the latter is pre-tensioned. The ring seal  86  is resting on the edge of the filter cup  14 . For better clarity, in  FIG. 14  the illustration of the ring seal  86  has been omitted. The filter element  18  is secured by the detent connection  20  in the filter cup  14  so that the latter, for joining with the filter head  16 , can be turned or tilted in all spatial directions without the filter element  18  falling out. In this manner, an assembly, hidden from view, f the filter cup  14  in the filter head  16  is easily possible. 
         [0083]    The filter cup  14  with the filter element  18  is screwed from below into the filter head  16 . In this context, the detent lugs  32  are still secured in the locking areas  40 . The ring seal  86  is resting in the installation position shown in  FIG. 1  tightly against suitable sealing surfaces at the inner wall of the filter head  16  and separates the clean side of the filter element  18  from the raw side. 
         [0084]    For dismantling, the filter cup  14  is unscrewed in opposite direction of rotation from the filter head  16 . In this context, by friction between the filter element  18 , in particular the ring seal  86 , and the filter head  16  it is effected that the filter element  18  is somewhat turned in the filter cup  14 . When doing so, the detent lugs  32  move out of the locking areas  40  into the respective translation areas  44 . Upon further unscrewing, the detent lugs  32  are guided along the translation areas  44  into the retaining areas  42 . By relative movement of the filter element  18  in axial direction out of the filter cup  14 , a volume is released at the bottom  34  of the filter cup  14  in which the residual oil is caught that is still contained in the filter housing  12 . In this manner, it is prevented that oil reaches the surroundings when exchanging the filter element  18  from the oil filter  10 . 
         [0085]    During the further opening phase of the filter housing  12 , the detent lugs  32  are retained in the retaining areas  42 . In this retaining position, the filter element  18  projects by about 1 cm out of the filter cup  14 . 
         [0086]    Moreover, the ring seal  86  is moved during the opening phase axially with respect to the rotation/insertion axis  30  relative to the filter element  18 . While unscrewing, the ring seal  86  remains in the filter head  16  until the guide projections  98  of the seal end disc  24  hit the boundaries of the guide gaps  96  at the free ends of the guide frames  94  of the support ring  88 . Thus, it is prevented that the oil escapes to the surroundings. 
         [0087]    The filter head  16  completely separated from filter cup  14  is turned upside down, so that its open side points downwardly. When doing so, the filter element  18  is retained with the detent connection  20  in the filter cup  14  so that it cannot uncontrollably fall from the filter cup  14 . This dismantling state is shown in  FIG. 15 . The representation of the ring seal  86  was omitted for better clarity. The filter cup  14  can be placed with the open side facing down for draining the oil, for example, into a drain pan or a different type of support. 
         [0088]    The filter element  18  is pressed with an impulse-like movement in axial direction into the filter cup  14 . This can be done, for example, by pressing with one hand onto the bottom  34  of the filter cup  14  wherein the free end face of the filter element  18  is pressed against the drain pan. In this connection, the switching lugs  76  of the dipping cylinder  70  are guided along the guide surfaces  82  of the switching guide  78  so that a rotation of the filter element  18  relative to the filter cup  14  is effected around the rotation/insertion axis  30 . 
         [0089]    With this rotation of the filter element  18 , the detent lugs  32  are moved from the retaining areas  42  into the insertion/removal areas  46  for deactivation of the detent connection  20 . In the insertion/removal areas  46 , the detent lugs  32  and the recesses  38  can be separated from each other unhindered. 
         [0090]    After deactivation of the detent connection  20 , the spiral compression spring  84  can relax and, in this way, causes the filter element  18  to be pushed in axial direction out of the filter cup  14 . When lifting the filter cup  14 , the filter element  18  remains in the drain pan. 
         [0091]    All together, the filter cup  14  with the filter element  18  can be mounted in a simple way with one hand even at hard-to-access and/or hidden sites, for example, in an engine compartment. A used filter element  18  can be exchanged simply with one hand and the oil-smeared filter element  18  itself must not be touched. 
         [0092]    In a second embodiment, shown in  FIGS. 5 to 8 , those elements which are similar to those of the first embodiment described in  FIGS. 1 to 4  are provided with the same reference characters so that with regard to their description reference is being had to the explanations relating to the first embodiment. This embodiment differs from the first one by the fact that the detent lugs  32  are arranged at the free ends of two detent wings  132  that are diametrically opposed relative to the rotation/insertion axis  30 . The detent wings  132  are arranged on a detent ring  133  which is fastened coaxially to the rotation/insertion axis  30  on the exterior side of the detent end disc  26  that is facing away from the filter medium  22 . The detent wings  132  extend basically in radial direction outwardly. The free ends of the detent wings  132  are bent in the same circumferential direction and form the detent lugs  32 . The detent guide  36  is configured similar to the detent guide  36  of the first embodiment. 
         [0093]    In the second embodiment, the switching guide  78  has switching angled members  182  instead of the progressing switching teeth  80  of the first embodiment. 
         [0094]    A moveable ring seal  186 , as shown in  FIG. 5 , is arranged in the second embodiment in axial direction between the seal end disc  24  and the detent end disc  26 . The ring seal  186  seals in the installed position, not shown in  FIG. 5 , in the area of the seal end disc  24 . 
         [0095]    In  FIG. 7 , a detail of the detent guide  36  is shown which includes alternative recesses  38  which are similar to the recesses  38  according to the first embodiment. 
         [0096]    The stationary cylinder  164  of the modular telescopic switching element  60  includes a central support sleeve  165  for centering the spiral compression spring  84 . The spiral compression spring  84  is embedded at one end in the end wall of the dipping cylinder  170 . The telescopic switching element  60  is shown in  FIG. 8  in isometric representation. 
         [0097]    In a filter element  18  according to a third embodiment, shown in  FIG. 9 , those elements which are similar to those of the first embodiment described in  FIGS. 1 to 4  are provided with the same reference characters so that with regard to their description reference is being had to the explanations provided for the first embodiment. This embodiment differs from first one in that, similar to the second embodiment, three detent wings  132  with the detent lugs  32  are provided in a distributed arrangement in circumferential direction and extend basically in radial direction outwardly. They are arranged in analogy to the second embodiment on a detent ring  133 . 
         [0098]    In addition, the third embodiment includes an alternative switching device  58  which is connected with a drain valve  135  that is of no further interest here. 
         [0099]    In a filter element  18  according to a fourth embodiment, shown in  FIG. 10 , four detent lugs  32  are provided instead of three detent lugs  32  of the first embodiment. This affects positively the force distribution when retaining the filter element  18  in the filter cup  14 . Further, the guide projections  98  for guiding the support ring, not shown in  FIG. 10 , for the slideable ring seal are arranged on a guide ring  200  that is coaxial to the rotation/insertion axis  30 . The guide ring  200  is fastened to the outside of the seal end disc  24  that is facing away from the filter medium  22 . 
         [0100]    In  FIG. 11 , a detail view of an axially slideable ring seal  86  with half moon-shaped profile is shown according to a fifth embodiment. The ring seal  86  is arranged, as in the first embodiment of  FIGS. 1 to 4 , on a support ring  88 . In contrast to the first embodiment, the guide projections  98  for guiding the guide frames  94  of the support ring  88  are however on the radial inner side of a cylindrical wall  202  of the seal end disc  24  of the filter element  18 . In addition, the seal end disc  24  includes a radial outwardly extending projection  204  which when the filter housing  12  is mounted is resting against an end face edge of the filter cup  14 . Between the opposed end face of the projection  204  and an appropriate end face edge of the filter head  16 , the ring seal  86  is arranged. In  FIG. 12 , the ring seal  86  of  FIG. 1  is shown in the relaxed state (I) and in the compressed state (II), as it exists when the filter housing  12  is mounted. 
         [0101]    In  FIG. 13 , an alternative recess  38  of a switching guide  78  is shown which is similar to the switching guide  78  of the first embodiment according to  FIGS. 1 and 4 . Here, a detent hook  232  is illustrated in dashed lines and includes the detent lug  32  at its free end. In contrast to the first embodiment, the retaining area  42  and the locking area  40  in each case have an axially extending projection  234  at their end that is facing the insertion/removal area  46  at the side that is facing the opening  48 . The projections  234  prevent the detent lugs  32  from unintentional rotation into the insertion/removal area  46  and thus from unintentional deactivation of the detent connection  20 . 
         [0102]    In a fifth embodiment, shown in  FIGS. 16 to 27 , reference is being had to the explanations provided for the first or second embodiment with respect to those elements which are similar to those of the first embodiment described in  FIGS. 1 to 4  and to those of the second embodiment described in  FIGS. 5 to 8 .  FIGS. 16 ,  18 ,  20  and  22  show a first assembly state during installation of the filter element  518  into the filter cup  514 .  FIGS. 17 ,  19 ,  21  and  23  show a final assembled state of the filter element  518  in the filter cup  514 . The representation of the filter medium on the support tube  28  was omitted in  FIGS. 16 to 27  for better clarity. In  FIGS. 20 and 21  the representation of the filter element  518  was omitted in favor of clear illustration of the telescopic switching element  560 . 
         [0103]    The fifth embodiment differs from the first and the second embodiment in that the switching device  558  includes a locking mechanism  559  which is activated in the basic state of the telescopic switching element  560  and blocks pushing together the telescopic switching element  560 . 
         [0104]    The dipping cylinder  570  of the telescopic switching element  560 , as shown in particular in  FIG. 27 , is shaped conically at its closed end face that is facing away from the stationary cylinder  564 . For better clarity, the spiral compression spring  584  which forces the dipping cylinder  570  away from the stationary cylinder  564  in the basic state of the telescopic switching element  560  is indicated only in  FIG. 17 . 
         [0105]    Three radial springy locking spring hooks  571  of the locking mechanism  559  are arranged in symmetric distribution relative to the rotation/insertion axis  530  in axial recesses in the circumferential wall of the dipping cylinder  570 . They extend in axial direction. Their free ends are located at the closed end face of the dipping cylinder  570  and project past the latter in axial direction. The free ends of the locking spring hooks  571  are formed to detent projections  573  which projects in radial direction outwardly. In the area of the detent projections  573 , the locking spring hooks  571  are bent radially in inward direction. 
         [0106]    The detent projections  573  project past the conical area of the dipping cylinder  570  in radial direction. On their sides facing away from the free ends of the locking spring hooks  571 , the detent projections  573  have locking steps  575 . The locking steps  575  project past the cylindrical segment of the circumferential wall of the dipping cylinder  570  in radial direction. 
         [0107]    The end wall at the closed end face of the dipping cylinder  570  includes circumferentially three indentations  577  which pass into recesses in which the locking spring hooks  571  are located. The locking spring hooks  571  can engage the indentations  577  by spring action in radial direction so that the radial outer sides of the detent projections  573  are positioned in radial direction at the level of the radial outer side of the cylindrical segment of the circumferential wall of the dipping cylinder  570  or even radially inside thereof. 
         [0108]    Between two of the locking spring hooks  571 , respectively, there is arranged one of a total of three spring hooks  572  on the radial outer side of the cylindrical segment of the circumferential wall of the dipping cylinder  570 . The spring hooks  572  are guided in three suitable guide slots  574  in the circumferential wall of the stationary cylinder  564 ; this is shown in particular in  FIG. 25 . The guide slots  574  extend axially relative to the rotation/insertion axis  530 . 
         [0109]    The stationary cylinder  564  includes in its circumferential wall between two of the guide slits  574 , respectively, one of a total of three locking guide slots  579  in which the detent projections  573  of the locking spring hooks  571  of the dipping cylinder  570  are guided. The locking guidance slots  579  extend axially relative to the rotation/insertion axis  530 . 
         [0110]    The edge at the open end face of the stationary cylinder  564  is beveled on the radial inner side, exclusive of those areas in which the locking guide slots  579  adjoin. In this manner, the spring hooks  572  are able to glide more easily into the guide slots  574  when assembling the telescopic switching element  560 . In the area of the locking guide slots  579  the edge of the stationary cylinder  564  is formed to locking stops  581  for the locking steps  575  of the locking spring hooks  571 . 
         [0111]    Between one of the guide slots  574  and one the locking guide slots  579 , respectively, a switching lug  576  is arranged on the radial outer side of the circumferential wall of the stationary cylinder  564  and extends in radial direction outwardly. The switching lugs  576  are approximately of parallelepipedal shape wherein two corners is slanted that, upon installation of the filter element  518 , are resting on a guide surface  582  of the switching guide  578  of the switching sleeve  562 , shown in  FIGS. 18 and 19  in particular. 
         [0112]    On the filter element  518  a release sleeve  583 , as shown in particular in  FIG. 24 , is arranged coaxially within switching sleeve  562 . The release sleeve  583  is adapted, for deactivation of the locking mechanism  559 , to the geometry of the locking spring hooks  571  of the dipping cylinder  570 . On the edge of the open end face of the release sleeve  583  the radius of its radial inner circumferential side is greater than the distance between the radial outer side of the detent projections  573  at the free end of the locking spring hooks  571  and the rotation/insertion axis  530 . In this manner, when inserting the telescopic switching element  560  into the switching sleeve  562 , the release sleeve  583  can press in radial direction from the outside against the detent projections  573  and bend the locking spring hooks  571  in radial direction inwardly. In this connection, the locking steps  575  are pushed away by the locking stops  581  of the stationary cylinder  564  in radial direction inwardly so that the locking mechanism  559  is deactivated and the telescopic switching element  560  can be pushed together. 
         [0113]    When it is attempted to install a filter element into the filter cup  514  without the release sleeve  583  that is matching the telescopic switching element  560 , the locking mechanism  559  remains activated and the telescopic switching element  560  cannot be pushed together. The extended telescopic switching element  560  prevents the installation of the filter element that does not fit, which is recognizable clearly from the outside. In this manner, limitations and/or disturbances of the filter function of the oil filter  510  which can be caused by using a filter element that does not fit are prevented. 
         [0114]    The release sleeve  583  includes at its free end face three indentations  585  which interrupt the edge of the release sleeve  583  in circumferential direction at uniform spacings. The indentations  585  extend in axial direction. The sides of the indentations  585  that are positioned to the rear when viewed in axial direction from the edge of the release sleeve  583  pass in each case into a slant located at the radial inner circumferential side of the release sleeve  583 . The indentations  585  are so arranged in circumferential direction with regard to the guide surfaces  582  of the switching guide  578  of the switching sleeve  562  that the engaged locking spring hooks  571 , in the final assembled state as shown in  FIG. 23 , are immersed in the indentations  585  and thereby can relax. In this manner, the mechanical load of the locking spring hooks  571  is reduced and their life span is increased. 
         [0115]    The switching guide  578  with the progressing switching teeth  580  is realized in the form of penetrations in the switching sleeve  562 . 
         [0116]    Within the release sleeve  583  there is a coaxial stop cylinder  587  and, in axial direction, the release sleeve  583  projects past it. Upon inserting the telescopic switching element  560  into the switching sleeve  562 , the dipping cylinder  570  with his closed end face hits the stop cylinder  587  and presses thus the dipping cylinder  570  in the stationary cylinder  564 . 
         [0117]    The activation and deactivation of the detent connection  20 , which includes the detent wings  32  and the detent guide  36 , by means of the switching device  558  functions in analogy to the above explained embodiments. 
         [0118]    In all of the above described embodiments of an oil filter  10 , a filter element  18 ;  518 , and a filter cup  14 ;  514 , the following modifications are possible inter alia: 
         [0119]    The invention is not limited to oil filters  10  of internal combustion engines in motor vehicles. Rather, it can be also used in different filters, for example, fuel filters or air filters, of internal combustion engines, industrial engines or compressors. A filter according to the invention can also be used in other technical fields of application. 
         [0120]    The filter medium  22  can be folded or formed differently than in a zigzag shape. 
         [0121]    The filter housing  12  can also be comprised of more than two housing parts. 
         [0122]    The filter cup  14 ;  514  can be mounted, instead of being suspended, also at an angle or standing upright from above on the filter head  16 . Instead of the filter head  16  a different housing part can be provided for attachment of the filter element  18 ;  518 . Instead of being screwed into or onto the filter head  16 , the filter cup  14 ;  514  can be connected also by means of another rotation and/or insertion connection, for example, a bayonet connection, in a releasable way with the filter head. 
         [0123]    Instead of the detent lugs  32 , different detent means can be also provided. Suitable detent means can be connected, instead of with the filter element  18 ;  518 , also with the filter cup  14 ;  514 ; the detent guide is then appropriately arranged at the filter element  18 ;  518 . 
         [0124]    The telescopic switching element  60 ;  560  or a suitable different switching device can be connected, instead of with the filter cup  14 ;  514 , also with the filter element  18 ;  118 . Accordingly, the switching guide  78  is then arranged at the filter cup  14 ;  514 . 
         [0125]    The switching device  58 ;  518  also can have more or fewer than two or three switching lugs  76 ;  576 . 
         [0126]    The switching device can also be arranged on a circumferential side of the filter element and the detent device can be arranged, instead, at the center of the detent end disc of the filter element. 
         [0127]    Instead of the spiral compression spring  84 ;  584 , a different elastic element, for example, a leaf spring or an elastic plastic element, can be provided also which is adapted to realize a restoring force. 
         [0128]    The filter element  18 ;  118  can project in the dismantling phase, in which the detent lugs  32 ;  532  are retained in the retaining areas  42 , also more or less than 1 cm past the filter cup  14 ;  514 . 
         [0129]    The retaining side  52  of the retaining area  42  and the locked position retaining side  57  of the locking area  40  can also extend within a plane that is perpendicular to the rotation/insertion axis  30 ;  530 . 
         [0130]    When the sides that are positioned respectively opposite the locked position retaining side  57  of the locking area  40  and the retaining side  52  of the retaining area  42  extend in a common plane perpendicular to the rotation/insertion axis  30 ;  35 , the translation area  44  can also extend within this plane. 
         [0131]    The detent connection and the switching device can also be combined. In particular, the detent connection can be designed in such a way, that the functions of the switching device realized and vice versa. 
         [0132]    The locking mechanism  559  for the telescopic switching element  560  and/or the release element  583  can be also designed to match each other in a different way. 
         [0133]    In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.