Abstract:
A sanitary mixing unit ( 1 ), in particular for wall installation, has a thermostatic device with a thermostatic element ( 16 ), and an excess travel spring ( 40 ) and a return spring ( 41 ) which act on the thermostatic element ( 16 ). A a sanitary mixing unit which is of simple and economical construction and with a low installation depth may be provided by the excess travel spring ( 40 ) and the return spring ( 41 ) acting on the thermostatic element ( 16 ) in the same direction, such that, in the case of excess travel, the spring forces of the excess travel spring ( 40 ) and the return spring ( 41 ) are additive.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a sanitary mixing faucet, especially for wall installation, with a thermostat means which has a thermostatic element, an over-travel spring and a reset spring acting on the thermostatic element. 
   2. Description of Related Art 
   A sanitary mixing faucet of the initially mentioned type is already known from published German Patent Application 195 02 147. In the known mixing faucet, the reset spring acts on one end of the thermostatic element, while the over-travel spring acts on the other end of the thermostatic element. In the known mixing faucet, the reset spring and the over-travel spring therefore act in the opposite direction, the over-travel spring generally having twice the spring force as the reset spring. Otherwise, in the known mixing faucet, the reset spring is used in conjunction with a multi-part reset means, while the over-travel spring is part of a multi-part over-travel unit. Ultimately, based on the arrangement of the reset spring, on the one hands and the over-travel spring, on the other, which arrangement is provided on opposite sides, and especially in conjunction with the reset means and the over-travel unit, a considerable amount of space is required; accordingly, this has an adverse effect on the construction depth of the mixing faucet. Moreover, the reset spring and the over-travel unit are comparatively complex assemblies; this has an adverse effect in terms of cost. 
   SUMMARY OF THE INVENTION 
   The object of this invention is to provide a mixing faucet of the initially mentioned type, which has a simple and economical structure and small structural depth. 
   The aforementioned object is essentially achieved in accordance with the invention in that the over-travel spring and the reset spring act on the thermostatic element in the same direction, so that the spring forces of the over-travel spring and the reset spring are added to one another in the case of an over-travel. In the embodiment in accordance with the invention, for the first time, a novel arrangement of the two springs is used, the over-travel spring and the reset spring being located on the same side with respect to the thermostatic element. This can greatly benefit the structural depth of the mixing faucet. Moreover, in the embodiment in accordance with the invention, in the case of over-travel, not only the over-travel spring, but also the reset spring act, and thus, the spring forces are added; ultimately, this results in the fact the an over-travel spring with a smaller spring force can be used. 
   In the embodiment which has an especially small space requirement, the over-travel spring and the reset spring are each made as helical springs, one spring being located within the other. By the arrangement of one spring within the other spring, no more space is required than is necessary anyway for the larger of the springs. 
   So that the two springs can easily engage the thermostatic element, a receiving part is provided which adjoins the thermostatic element on one side and the over-travel spring and the reset spring jointly on an opposite side. In this way, a conventional thermostatic element can be used. 
   Preferably, with respect to a space-saving execution, there is a temperature control part which is made as a sleeve and the over-travel spring and reset spring are located within the temperature control part. Thus, ultimately, the space which is necessary anyway for the temperature control part is now used for the two springs, without the need for special additional space for the springs. In this connection, it is a good idea for the over-travel spring to be supported on the peripheral collar which is preferably provided within the temperature control part, while the reset spring is supported on a housing part which is stationary in the axial direction relative to the temperature control part. 
   Moreover, it is advantageous if the receiving part is located within the temperature control part, the entire execution of the cartridge being such that the supplied hot water is routed through the temperature control part. This ensures that unmixed hot water flows onto the receiving part in the inflow direction. In this connection, it is an especially good idea to allow the thermostatic element to rest with its thermostatic area against the receiving part such that a smaller part of the thermostatic area is exposed to the flow of unmixed hot water, the larger part of the thermostatic area being exposed to the flow of mixed water. The partial exposure of the thermostatic area of the thermostatic element to the flow of unmixed hot water leads to movement of the temperature control part which is made as a sleeve in the “cold” direction, the hotter the incoming hot water. In this way, it is possible to compensate for the systematic error of thermostats of conventional design which arises when the inflow temperature of the hot water fluctuates. 
   Finally, it is preferred that the arrangement of the over-travel spring and the reset spring in accordance with the invention be implemented in a cartridge which represents an inherently manageable and closed unit. It goes without saying that this invention also relates to one such cartridge. 
   One embodiment of this invention is explained in detail below with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of part of the mixing faucet in accordance with the invention, 
       FIG. 2  is an exploded view of the part of the sanitary mixing faucet shown in  FIG. 1 , 
       FIG. 3  is an exploded view of parts of the mixing faucet in accordance with the invention, 
       FIG. 4  is an enlarged perspective of a cartridge in accordance with the invention, 
       FIG. 5  is a cross-sectional view of a cartridge in accordance with the invention, 
       FIG. 6  is a cross-sectional view of a cartridge in accordance with the invention rotated 90° about its longitudinal axis relative to the representation in  FIG. 5 , and 
       FIG. 7  is an exploded view of the individual parts of the cartridge in accordance with the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1 and 2  show a portion of a sanitary mixing faucet  1  which is intended especially for wall installation. The mixing faucet  1  has a base body  2  which has a cold water supply connection  3 , and has a hot water supply connection on the opposite side (not shown). A receiving sleeve  5  for the cartridge  6  is locked into the receiver  4  of the base body  2 . The cartridge  6  makes it possible to adjust the amount and temperature of the mixed water. For this purpose, the mixing faucet  1  has a quantity adjustment means and a temperature adjustment means in the cartridge. Furthermore, there is a thermostat means in the cartridge  6 . The cartridge  6  is fixed in or on the receiving sleeve  6  via a locking nut  7 . 
   Supplementing the parts shown in  FIG. 2 ,  FIG. 3  shows a covering sleeve  8  which is pushed over the receiving sleeve  5 , a first twist operating handle  9  and a second twist operating handle  10  which is composed of several parts and which can be attached to the front of the cartridge  6  via a screw  11 . 
   As follows especially from  FIGS. 5 and 6 , the mechanism for controlling the quantity and temperature is implemented in or on the cartridge  6 . For this purpose, the cartridge  6  itself has an outside housing  12  in which, among other things, there are a stationary valve disk  13  and a rotating valve disk  14  of the quantity adjustment means which interacts with it. 
   It is significant, at this point, that the inside housing  15  can be coaxially turned in the outside housing  12  by at least 180° around the axis D which is the central lengthwise axis of the cartridge  6 . There is a thermostat means which has a thermostatic element  16  in the inside housing  15  and it is thus turned at the same time as the inside housing  15  is turned relative to the outside housing  12 . Furthermore, the rotating valve disk  14  is rotationally fixed on the inside of housing  15  so that the valve disk  14  is turned at the same time as the inside housing  15  is turned relative to the outside housing  12 . Conversely, the stationary valve disk  13  is rotationally fixed relative to the outside housing so that, when the inside housing  15  turns, motion of the movable valve disk  14  takes place relative to the stationary valve disk  13 , which is not moving. 
   As a result, the aforementioned configuration means that the cartridge  6 , which is inserted into the receiving sleeve  5  and the receiver  4  of the base body  2 , need not be removed from the above described installation position for adaptation to the respective structural circumstances, but that, simply, the inside housing  15  need only be turned by 180° around the axis D in order to ensure faultless operation of the mixing faucet  1 , depending on the location of the water supply connections. In this connection, in order to otherwise prevent the outside housing  12  from turning at the same time as the inside housing  15  turns, there are corresponding fixing projections  17  on the end of the cartridge  6  for interaction with openings in particular on the base body  2  and on the receiver  4  (not shown). 
   On the end face, i.e., on the side facing the user, the inside housing  15  is routed out of the outside housing  12  with the engagement section  18 . The first twist operating handle  9  for adjustment of the quantity can be slipped onto the engagement section  18 . To slip the first twist operating handle  9  onto the engagement section  18  and for preventing relative rotation of the twist operating handle  9 , a groove  19  is provided which runs in the lengthwise direction of the cartridge  6  and which interacts with a corresponding projection  20  on the first twist operating handle  9 . In the embodiment shown, there are grooves corresponding to projections  20  on opposite sides of the engagement section  18  and in the corresponding insertion opening of the first twist operating handle  9 . 
   To be able to adjust not only the quantity, but also the temperature, from the end face of the cartridge  6 , the temperature adjustment means has an engagement section  21  which projects out of the end face of inside housing  15  for seating of the second twist operating handle  10 . In the installed state, with the twist operating handles  9 ,  10  attached, the first twist operating handle  9  and the second twist operating handle  10  have the same axis of rotation, i.e., the axis D. 
   As follows from  FIG. 7 , the valve openings  22 ,  23 ,  24 ,  25  which are provided in the two valve disks  13 ,  14  extend over less than 90°, the maximum opening cross section arising after a rotary motion of roughly 90°. 
   Basically, it can be provided that the inside housing  15  can be turned by only 180° relative to the outside housing  12  by the corresponding stops. However, there are no such stops here. For adjusting the quantity, there are means for limitation of the rotation of the first twist operating handle  9  which enable it to be rotated by only roughly 90°. In particular, the means for limiting rotation of the first twist operating handle  9  has a guide groove  26  which runs on the periphery of the outside housing  12  and into which the projection  20  fits. The guide groove  26  extends over an arc length of roughly 90° so that the maximum rotation of the first twist operating handle  9  is dictated thereby. Otherwise, on the outside housing  12  and on the projecting engagement section  18  of the inside housing  15 , corresponding markings  27 ,  28  are provided for indicating the state of rotation of the inside housing  15  relative to the outside housing  12 . 
   As follows especially from  FIGS. 5 and 6 , the cartridge  6  with the components contained therein represent an inherently manageable and closed unit. The cartridge  6  is comprised of a host of components which are shown in particular in  FIG. 7 , even if not all parts are described in particular. A bottom plate  29  is locked to the outside housing  12  to close the cartridge  6 . Here, the fixed valve disk  13  on the bottom plate  29  so that, in this way, relative rotation with respect to the outside housing  12  easily prevented. 
   As follows from  FIG. 5  to  7 , the inside housing  15  is made in several parts; adjacent parts of the inside housing  15  are connected so that relative rotation with respect to one another does not occur. The inside housing  15  has an upper inside housing part  30  with the engagement section  18 . The inside housing part  30  is connected to the inside housing part  31 , between the inside housing parts  30 ,  31  there being a set screw  32  and an adjustable nut  33  for achieving axial motion of the thermostatic element  16  and the associated components. On the outside, on the set screw  32 , there is an engagement section  21  for the second twist operating handle  10  for adjustment of the temperature. Furthermore, between the two inside housing parts  30 ,  31 , there is a thermostatic element  16  which is made as an expansion element and which is held with one end in the corresponding receiver  34  of the adjustable nut  33 . 
   The inside housing part  31  adjoins two other comparatively narrow inside housing parts  35 ,  36 , between which a sealing membrane  37  is held. Finally, there is a lower inside housing part  38  which adjoins the inside housing part  36 . For bracing the sealing membrane  37 , the inside housing parts  31 ,  35 ,  36  and  38  are attached to one another via the corresponding screws  39 . 
   As follows especially from  FIGS. 5 and 6 , an over-travel spring  40  and a reset spring  41  which are located likewise within the cartridge  6  act on the thermostatic element  16 . In this connection, it is important that the over-travel spring  40  and the reset spring  41  act on the thermostatic element  16  in the same direction, here specifically in the direction of the arrow F so that the spring forces of the over-travel spring  40  and the reset spring  41  are added to one another in the case of an over-travel, therefore when the length of the thermostatic element changes. 
   In this embodiment, the over-travel spring  40  and the reset spring  41  are located on the same side of the thermostatic element  16 . Here, an especially space-saving arrangement is achieved in that the over-travel spring  40  and the reset spring  41  are each made as helical springs, the reset spring  41  being located within the over-travel spring  40 . 
   To transfer the spring forces of both the over-travel spring  40  and also the reset spring  41  to the thermostatic element  16  and to make contact between these springs and one end of the thermostatic element  16 , a cross-shaped receiving part  42  is provided which has flow openings. The receiving part  42  has an external flange-like engagement section  43  and an axially extending journal  44 . The over-travel spring  40  adjoins the engagement section  43 , while the reset spring  41  is seated on the journal  44 . The thermostatic element  16  rests on the opposite side of the receiving part  42 . The over-travel spring  40  and the reset spring  41  have roughly the same spring force, specifically roughly 50 N each. 
   Here, a sleeve which is supported in the inside housing  15  is used as the temperature control part  45  on which the thermostatic element  16  acts. The receiving part  42  is located within the temperature control part  45  and is pressed via the over-travel spring  40  against the inner stop of the temperature control part  45 . The temperature control part  45  has control edges on its end faces for the hot and cold water. With reference to  FIGS. 5 and 6 , the hot water control edge is located on the left side, the cold water control edge on the right side of the temperature control part  45 . The hot water, in the unmixed state, strikes not only the receiving part  42  which is located within the temperature control part  45 , but also the thermostatic area of the thermostatic element  16  which directly adjoins the receiving part  42 . This ensures that the unmixed hot water flow flows against part, preferably the smaller part, of the thermostatic area of the thermostatic element  16 , while mixed water flows around the other, larger part of the thermostatic area of the thermostatic element  16 . 
   In order to optimally use the available space in the inside housing  15 , the over-travel spring  40  and the reset spring  41  are located within the temperature control part  45 . In doing so, the over-travel spring  40  which is used to reset the temperature control part  45  is supported on the side opposite the receiving part  42  on the peripheral collar  46  of the temperature control part  45 , while the reset spring  41  which is used also to hold the thermostatic element  16  is supported on the inside housing part  38 . For this reason, there is a corresponding journal  47  on which the reset spring  41  is seated.