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CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a United States National Phase application of International Application PCT/EP2007/009616 and claims the benefit of priority under 35 U.S.C. §119 of German Patent Application DE 20 2006 016 981.4 filed Nov. 7, 2006, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a combination device for performing different tasks such as snow throwing, mowing, scarifying, soil breaking, sweeping or the like by means of interchanging the work implements such that each implement is adapted for each respective task, whereby a machine frame is intended for taking on the respective work implement and letting it be driven in rotation, and that the respectively installed work implement is enclosed by a partially open cylindrical housing the rotational axis of which lies in parallel to that of the work implement. 
     BACKGROUND OF THE INVENTION 
     Combination devices of such nature have been known in various guises in the past: 
     DE 2 017 981 A discloses one such combination snow thrower consisting of a basic machine. On such machine, various work implements can be interchanged by pulling out the axle pin. Work implements in cylindrical form can be used for tasks like salt sprinkling, snow clearing, ice and earth breaking, as well as lawn mowing and sweeping. Such cylindrical work implements can be rotated about an axis horizontal and parallel to the ground by means of a motor on board the machine. 
     In order to throw snow, a cylindrically shaped snow throwing drum with transverse shoveling paddles as described in DE 2 017 981 A is used. Ice breaking is another feature of the device which can be realized by replacing the snow throwing drum with a steel spiky one. For sweeping of powdery snow, garden debris or the like, a sweeping drum can be deployed with steel or plastic bristles. For soil breaking, a tilling drum is used, whereby it is combined with paddle wheels that are covered and together with which the dug up soil will be blown to the side. For lawn mowing, a cutting reel is used whereby the grass clippings are blown forward by the paddle wheels (fan) into a container. The cutting reel takes the form of two cutting knives with two sweeping brushes located at the back and which are intended for sweeping grass cuttings into the fan. 
     Another feature of the device in DE 2 017 981 A has a spreader that can be additionally attached to it for the purpose of sprinkling salt as well as soil fertilizer. Such combination device is penalized by the fact that not all its functionalities can be optimally designed for all the work tasks. In particular, in the case of snow throwing, a discharge chute is not provided for displacing snow at a further distance away during or at the end of the snow cutting process. 
     DE 31 00 904 C2 refers to another embodiment of a motorized walk-behind machine for snow clearing, sweeping or scarifying. This machine shows a basic housing into which various work implements, as described already in DE 2 017 981 A, can be accommodated. 
     According to DE 31 00 904 C2, additional side wheels can be mounted onto the housing such that the machine can be used as a scarifier. The side wheels however have to be mounted separately. Another disadvantage lies in the drive axis which, depending on the functionality, is supported from one side only, thereby leading to instability. In order to utilize the device as a sweeping machine or a snow thrower, the fixed housing and machine together are rotated about the work implement axis, thereby being brought into two distinctly different inclinations relative to ground. Furthermore, the device may for example be hampered by its inability to allow for height adjustment or the separation between the work implement and ground. The device is generally penalized in terms of its handling. 
     DE 38 12 105 C2 proposes a combination device for garden and roads. The embodiment includes a housing that is forwardly half open and which caters for different work implements. The work implements in turn are housed within their own casings both of which can be mounted and fixed onto the main device housing. Work implements for lawn mowing, scarifying, throwing snow, sweeping and blowing have also been mentioned. 
     According to DE 38 12 105 C2 and the claims therein, the work implements with their respective housings can be shifted sideways and subsequently locked into position within the device housing. In operation, the axis of the work implement is mechanically coupled to the device&#39;s own actuator by means of a pinion. The device is extremely troublesome to set up and requires individual housing for each work implement to be attached onto the main device housing. 
     The combination device as referred to in U.S. Pat. No. 4,064,679 A shows yet another embodiment that can be adapted for lawn mowing, snow throwing and lawn sweeping. Due to the inter-changeability of individual work implements, the device is also capable of multiple tasking. However, the changing of work implements is complicated by the housing, whose side wall has to be physically dismounted first, by undoing a number of bolts, before finally being able to change over the work implements. Additional housing covers or housing attachments are included for the different functionalities, which further complicate the tool setup not to mention the provision for additional storage of individual parts. 
     SUMMARY OF THE INVENTION 
     The deficiency just described is overcome in accordance with the present invention wherein the changing of different work implements is simplified and functionally optimized. 
     The work task is fulfilled by a combination including inter-changeable work implements which adapt to the tasks in the respective operating configurations, a base frame onto which the respective work implements can be mounted and driven in rotation and whereby the individually built in work implement is partially enclosed by a housing that runs parallel to the rotation axis of the work implement. The housing is rotatable about an axis parallel to the drive axis of and can be locked into its respective position depending on the work task at hand. 
     Tool changing is hence made much easier through the rotatable housing of the combination device. Furthermore, tool changing is facilitated by having the housing only partially enveloping the work implement thereby permitting the necessary access. On the other hand, the housing can be brought to different positions, such that individual work tasks are optimally performed within the necessary work implement enclosure. 
     In the preferred embodiment, the housing encloses the work implement over a wrap angle such that the housing opens itself relatively forward and downward in the first operating position, mostly downward in the second operating position, and relatively backward and downward in the third operating position. Through such arrangement, snow throwing for example can be optimally performed when the housing is fixed with its opening facing the front and pointing downward. Lawn mowing for example can equally and optimally be performed by having the housing face downward and backward. 
     According to other features, the housing is equipped with rollers, wheels or rolling cylinders along its front and back edges that run parallel to the axis of work implement&#39;s rotation in such a way that the housing is supported off the ground by its back set of rollers, wheels or rolling cylinder when in the first operating position, the housing is not supported by any rollers, wheels or rolling cylinder when in the second operating position, the housing is supported off the ground by its front set of rollers, wheels or rolling cylinder when in the third operating position. 
     In the case of snow throwing, instead of rollers, wheels or rolling cylinder, the housing can also be supported by conventional skids which is height adjustable. The possibility for height adjustment also applies to the rollers, wheels or rolling cylinder. 
     The housing may be fitted with a scraper bar along its back edge in order to take up snow while the device is being used as a snow blower, and that the housing exhibits an opening in its first operating position on top of which a discharge chute can be attached. Through this configuration, the housing is best optimized for snow throwing. Through the rollers, wheels or rolling cylinder, the height of the scraper bar can be adjusted relative to ground in such a way that the combination device can best adapt to the respective working conditions. 
     The housing comprises two side walls that can be mounted in relative rotation to the two side plates of the basic frame, and that in the first side plate, provision is made for the transmission axle, and that in the second side plate, an axle journal is available, such that the inter-changeability and the rotation of different work implements and their adjustability can be catered for. Through this configuration, the work implements can be changed over easily and secured within a cost-effectively and simply designed housing. 
     The transmission axle is belt driven and that the respective work implements are coupled in rotation to and detachable from the transmission axle. Such form of transmission is especially easy to maintain. 
     The base frame may form an integral part of the basic machine, and the basic machine exhibits means of transport in the form of wheels, with which the basic machine together with the base frame and the respective work implement can be driven on the ground. The basic machine may have wheels which are height adjustable. The wheels can be free running such that the combination device can simply be pushed along by hand. To lighten the work load, the same wheels can be motorized and whose coupling can be switched on or off. 
     A motor actuator may be provided to drive the work implements via a pulley belt or the like. This motor actuator can also be used for driving the wheels via a switchable gear set. 
     The configuration of the different interchangeable work implements, especially in relation to snow throwing, mowing, scarifying, soil breaking or sweeping are also described. It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components as set forth. 
     As far as a self-contained walk-behind combination device is concerned, the wheels can also be driven by the on board motor actuator, as in the examples of snow throwing or lawn mowing, and the actuator in turn can also be switched on or off at will. 
     The combination device can also be so configured that it can be built onto a communal care vehicle, a tractor or the like in the form of an attachment. Here also, it can be seen that the rotatable housing will facilitate the changing over of work implements as well as its optimal operation. 
     All the work implements have in common a cylindrical form and that their axis of rotation is relatively parallel to the ground being worked on and runs across the direction of machine travel. 
     The invention in its preferred embodiment will now be described and become more readily apparent on examination of the following description, including the appended drawings. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a perspective view of the invention, namely the combination device with a rotatable housing excluding the work implement; 
         FIG. 2  is a front view II of the combination device housing as referred to in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view through the bearing fixture of the drive axis within the housing as referred to in  FIG. 2 ; 
         FIG. 4  is a perspective view of the combination device as referred to in  FIG. 1 ; 
         FIG. 5  is a perspective view of one work implement in the form of an augur for use with the combination device as a snow thrower; 
         FIG. 6  a perspective view of the combination device as referred to in  FIG. 1  with the augur as referred to in  FIG. 5  as well as a discharge chute as mounted onto the housing; 
         FIG. 7  a partial view VII of the snow thrower as implemented from the combination device in  FIG. 6 ; 
         FIG. 8  is a perspective view of one work implement in the form of a mowing reel with the so called upper blades equally spaced along its circumference; 
         FIG. 9  is a perspective view of a so-called bed-knife which can be combined with the mowing reel in  FIG. 8  of the combination device to become a lawn mower; 
         FIG. 10  is a perspective view of the combination device showing the housing with the attached mowing reel as well as the bed-knife; 
         FIG. 11  a partial side view XI of the combination device as referred to in  FIG. 10 ; 
         FIG. 12  is a perspective view of a work implement in the form of a scarifying cylinder with spring tines radiating substantially outwards; 
         FIG. 13  a partial side view of the combination device with the attachment of the scarifying cylinder as referred to in  FIG. 12 ; 
         FIG. 14  is a perspective view of a work implement in the form of a tilling cylinder in perspective view; and 
         FIG. 15  is a partial side view of the combination device with the attachment of the tilling cylinder as referred to in  FIG. 14 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings in particular,  FIG. 1  shows the principal configuration of a combination device  1  in its perspective view. 
     To the rear of the combination device  1 , a wheel frame  2  is shown and which comprises two bent guide rods  3  and  4 , whose upper ends transform into the respective hand grips  5  and  6 . At the lower end of the guide rods  3  and  4 , two wheels  7  and  8  are mounted by means of fixture  9  which enables height adjustment along the guide rods  3  and  4 . 
     Furthermore, the combination device exhibits a base frame  10 , whose front end is mounted with two vertical side plates  11  and  12 . The side plates  11  and  12  are fixed onto but detachable from the base frame  10 . The base frame  10  is bolted together with the lower parts of the guide rods  3  and  4  by means of the palm grip  13 . 
     In order to support and strengthen the combination device  1 , a stiffening bracket  14  is seen in the present embodiment with one end being attached to the guide rods  3  and  4  by means of the palm grip  15 , while the other end being attached onto the base frame  10  by means of fixtures  16 . Furthermore, a motor engine  17  can be seen in the present embodiment mounted onto the base frame  10 , and whose very outer end is mounted with a belt pulley  18 . 
     The belt pulley  18  is connected to another belt pulley  19  via a pulley belt  20 . This pulley  19  serves the purpose of driving the transmission axle  21 , the detailed function of which will be described later. 
     Lying coaxially to the transmission axle  21 , a gudgeoning pin  22  is seen to the right side of the “rear” side plate  12 , and which forms a straight line with the transmission axle  21 . This gudgeoning pin  22  as well as the transmission axle  21  can be axially and outwardly retracted in order to allow for the easy changing over of work implements. 
     It is worth noting here that the basic design of the combination device  1  is capable of other embodiments. Important being the two side plates  11  and  12  with a housing  23  sitting in between. The housing  23  can be swung or pivoted about the transmission axle  21  as well as the journal  22  on both side plates  11  and  12 , which is shown in the first operating position in  FIG. 1 . In the same operating position, it can be seen that the housing  23  is bolted down by means of two security bolts  24  one of which can be seen in  FIG. 1 . 
     It can also be seen in  FIG. 1  that the housing  23  is shown with two side walls  25  and  26  that enable the housing to be mounted about a rotational axis parallel to the transmission axle  21  and to the gudgeoning pin  22 . 
     Further details on the housing  23  will be explained later with reference to  FIG. 4 . 
       FIG. 2  shows the front view II, in particular, that of the housing  23  as in  FIG. 1 . It is noticeable that the housing  23  with its side walls  25  and  26  is fitted in between the two side plates  11  and  12 . These assembly side plates  11  and  12  have on their inner sides clamp rings  27  and  28  that couple the housing  23  with its side walls  25  and  26  and enable them to rotate. The second security bolt  24  can also be seen in  FIG. 2 . 
     It can be further seen that the gudgeoning pin  22  projects into the housing  23 . The transmission axle  21  also displays a drive element  29  that partially projects into the housing  23 . The drive element  29  shows two diametrically opposite and radial projecting drive keys  30  and  31 , via which the transmission axle  21  can be rotationally coupled onto the respective work implement within the housing  23 . 
       FIG. 3  shows an enlarged view of the transmission axle  21  in the area of the assembly side plate  11 . It can be seen that the drive pulley  19  is rotationally mounted with bearings  32  and  33  along the axle on either of its extreme end. The bearing  33  is seated respectively on the assembly side plate  11 . A support plate  34  outside at a distance away from and fixed onto the assembly plate  11  is as shown in  FIG. 1 . The drive pulley  19  is drilled with a hole  35  in the center the inner side of which is cut with two diametrically opposite key slots  36  and  37 . In this key slot, the two drive keys  30  and  31  of the transmission axle  21  can be form fittingly taken up and remain axially adjustable. From the engaging position as shown in  FIG. 3 , the transmission axle can be seen axially adjustable in the direction as indicated by the arrow  39  by means such as spring actuation (not shown here) and alike, to such extent that a work implement can be inserted in between the side walls  25  and  26  of the housing  23 . 
     The fixation for the gudgeoning pin  22  is also designed in a similar fashion. In  FIG. 3 , the tooth belt  20  can also be seen. 
     As already mentioned previously,  FIG. 4  shows the housing  23  in perspective view. This view of the housing  23  is already presented as the first operating configuration in  FIG. 1 . The housing  23  comprises a partially open cylindrical outer wall  40 , which is fitted or for example welded with the side walls  25  and  26 . To the front of the outer wall  40 , there is a reinforcement fixture  41  formed on top and the front end within which is seen with a bearing shaft  42 . The bearing shaft projects out of the two side walls  25  and  26  such that on either side the wheels  43  and  44  are supported accordingly. 
     To the back and at the bottom of the outer wall  26 , a lug plate  45 / 1  is shown here together with a second lug plate not displayed in the drawing, the purpose of which is to provide support for the back wheels  45 . 
     Furthermore, it can be seen in  FIG. 4  that in the rear edge  46 / 1  location of the housing  23 , a scraper  46  is provided whose function corresponds to that of a snow thrower. 
     On the top of the outer wall  40 , an opening  47  can be further seen in the vicinity of which a chute adapter  48  is fitted. The chute adapter  48  serves as a removable mounting platform for the blowing chute  49 , as shown in  FIG. 6  that can be typically found in the state-of-the-art snow thrower. 
     On both the side walls  25  and  26 , locking fixtures  50  and  51  can be seen projecting radially with the purpose of fixing the housing  23  in between the assembly side plates  11  and  12  in the respective operating configuration. In the corresponding configuration, fixation holes  52  can also be seen on the assembly side plate  11  and  12 , as shown in  FIG. 6 . The second fixation hole in the lower region of the side wall  11  is seen here hidden by the security bolt  24 , which projects and typically locks through the lower fixture hole  50  on the side wall  25  of the housing  23 . The fixing of the security bolts  24  can be realized by means of bolt nuts  53  and  54  welded onto the locking holes  50  and  51 . 
     It can be seen further in  FIG. 4  that both side walls  25  and  26  have round apertures  55  and  56 , upon which the respective assembly side plates  11  and  12  can be rotationally located, as shown in  FIG. 2 . 
     For the combination device  1  to perform as a snow thrower, as shown in  FIGS. 1  and  6 , a snow augur  60  is shown in  FIG. 5 , the front portion of which a coupling element  61  can be seen via which the transmission axle  21  with its key elements  30  and  31  can be coupled in firm rotation. On the other end of the rotational axle  62 , opposite to the coupling element  61 , an insertion hole can be found but which is not shown here in  FIG. 5 . Further description on the snow augur  60  is deemed unnecessary as it conforms to the state-of-the-art. 
       FIG. 6  shows the combination device  1  in its snow throwing configuration. It can be recognized that the housing  23  circumscribes the snow augur  60  partially, hence exposing the housing  23  forward in the travelling direction as indicated by the arrow  63  as well as backwards. The wheels  43  and  44  as described in  FIG. 4  are functionally redundant in this operating state of the housing  23 . On the contrary, the wheels  45 , the configuration of which corresponds to those of the wheels  43  and  44 , are mounted onto the housing  23  in order to support the combination device  1  on its front end. This can be seen in particular from the side view as shown in  FIG. 7 . 
     It is noticeable that the wheels  45  are being supported by the ground  64 , hence defining through the same wheels  45  the vertical separation between the scraper  46  and the ground. By adjusting the height via the wheels  7  and  8  as shown in  FIG. 6 , a pivotal movement will be resulted in the direction as shown by the double arrow  65  ( FIG. 7 ) with the whole combination device  1  pivoting about the rotating axis of wheels  45 , thereby enabling the vertical separation between the scraper  46  and the ground  64  to become adjustable. In this respect, the snow throwing function can be optimally adapted by means of special features such as those located on the housing  23  together with the wheels  45 . It can be seen further in  FIG. 7  that the first operating configuration is fixed by means of the security bolt  24 . 
     Apart from height adjustment via the wheels  7  and  8 , other means of setting the separation between the scraper  46  and the ground  64  is also possible and easily achievable within certain limitation. 
       FIG. 8  shows a mowing reel  70 , as is generally regarded as state-of-the-art. The mowing reel  70 , as shown in  FIG. 8 , comprises a multiple of so-called upper blades  71  which act together with the so-called lower blade  72 , as shown in  FIG. 9 , to perform the grass cutting function. It can also be seen in  FIG. 8  at the right hand side of the reel cylinder that the coupling journal  73  is equipped with two radially projecting take up slots  74  and  75 . With the slots  74  and  75 , the mowing reel  70  can be attached to the transmission axle  21  in firm rotation via the drive element  29  as well as the two radially projecting key elements  30  and  31  ( FIG. 2 ). On the opposite end of the mowing reel spindle  70 , a fixation hole  76  is located, into which the gudgeoning pin  22  of the assembly side plate  12  in  FIG. 2  can be inserted. 
     The lower blade  72  has two side mounted bolts  77  and  78 , with which the lower blade  72  can be mounted to the assembly side plates  11  and  12 , as shown in  FIG. 10  out of the bottom view of the combination device  1 . The lower blade  72  can be adjusted in relation to the upper blades by means of two side adjustment screws  79  and  80 , such that mowing can be adapted to various cut quality. It is also possible to have the mowing spindle  70  together with the lower blade combined into one module which can then be inserted into the housing  23  of the combination device  1 . 
     Referring to  FIG. 10  and  FIG. 11 , the housing  23  is now set in its third operating configuration as that of a lawn mower. In this third configuration, both wheels  45  as shown in  FIG. 10  are rendered functionally redundant. On the other hand, both the other wheels  43  and  44  are now in contact with the ground  64 , such that the “frontal piece” of the whole combination device  1  is supported by the wheels  43  and  44 . This results in a vertical separation as can be seen in  FIG. 11 , between the group of blades, comprising the upper blades  71  and the lower blade  72 , and the ground  64 . 
     In the third operating configuration, the housing  23  is firmly bolted down by means of the security bolts  24 . The height adjustment is also made possible here via the wheels  7  and  8  that are attached onto the frame pillars  3  and  4 , thereby producing a pivotal effect on the combination device  1  about the rotation axis of the wheels  43  and  44 , the direction of which is as indicated by the double arrow  65 . In this way, a height adjustment is also catered for in the mowing function by setting the distance between the blades, both upper blades  71  and lower blade  72 , and the ground  64 , so as to achieve the required cutting height. 
     In this configuration of the combination device  1 , the snow throwing chute  49  in  FIG. 6  is without saying no longer needed and will be dismantled accordingly. The opening  47  as shown in  FIG. 10  which functions as the snow throwing chute adapter  48  as shown in  FIG. 11  is preferably to be covered up by means of say a protection cover which is not shown here in the drawing. 
     Referring to  FIG. 10 , a basket for grass collection, which is not shown here, can be placed behind the housing  23 . The basket can also serve as a protection device for the user who drives behind the combination device  1 . Such a basket can also be adapted for the scarifying, tilling or sweeping functions. 
       FIGS. 12 and 13  show another function of the combination device  1 , whereby  FIG. 12  shows the work implement in the form of a scarifying cylinder  85 . This scarifying cylinder  85  comprises a multitude of spring tines  86  that radiate out of the rotational axis and serve as means of aerating the soil in the lawn. The scarifying cylinder  85  in the presented form or in form equipped with radial airing blades is state-of-the-art and whose examples are plentiful. 
     In  FIG. 12 , the scarifying tool  85  is shown with an adapter at its end and two radial slots  88  and  89 , with which the scarifying tool  85  can be coupled in firm rotation to the drive element  29  of the transmission axle  21  via the two drive keys  30  and  31  (see  FIG. 2 ). 
       FIG. 13  shows the configuration of the combination device  1  as scarifier. It can be noticed that the housing  23  is set up in the same third operating configuration as when the combination device  1  is used as mower, as shown particularly in  FIG. 11 . Accordingly the operating configuration is fixed in position by means of the security bolts  24 , whereby the wheels  45  are also made redundant here. The housing  23  is supported off the ground  64  by the wheels  43  and  44  in such a way that the penetrating depth of the spring tines  86  can be adjustably defined. Through the height adjustment of wheels  7  and  8  at both the frame pillars  3  and  4  ( FIG. 1 ), the whole combination device  1  can thus be seen pivoting about the bearing axis of the wheels  43  and  44  in direction as indicated by the double arrow  65  such that the penetrating depth of the spring tines  86  can also be adjusted. 
     The combination device can be easily set up to function as scarifier. The housing  23  is there, as can clearly be recognized in  FIG. 13 , opening itself up from beneath and towards the rear against the direction of travel as indicated by the arrow  23 . 
     In yet another implement, the combination device  1  can be used as a tiller. To this, a work implement typically in the form of a tilling cylinder  95  can be seen in  FIG. 14 . The tilling cylinder  95 , as is general known as the state-of-the-art, comprises the so-called cleavers which are used for ground breaking and soil loosening. 
       FIG. 15  shows part of the side view of the combination device  1 , onto which the tilling cylinder  95  with its cleavers  96  is mounted. It can be seen that under this condition, the runners  45  as well as the runners  43  are made functionally redundant. This means that the housing  23  is fixed in its second operating configuration, and in this case bolted down to the assembly side plates  11  and  12  by the security bolts  24 . On account of this arrangement, the cleavers  96  project well beneath the housing  23  such that a reasonable soil depth penetration can be achieved here. By controlling the handgrips  5  and  6  of the combination device  1 , an optimal soil loosening is made possible. 
     Instead of the exemplary work implements presented here so far, other cylindrical work implements such as a sweep roller can also be deployed. Through the respective turning of the housing  23 , such a sweep roller in the desired form can be hidden either towards the rear or partially towards the front, so that the combination device  1  can easily be converted into a sweeping machine. If the sweep roller is hidden by the housing  23  towards the front, then a sweep collector can be placed towards the rear for catching all the swept material. In this embodiment, the reversal of the direction of rotation will not be necessary as far as the sweeping function of the combination device  1  is concerned. 
     In particular, with regards to the height adjustment for the respective work implements or their distance of separation relative to ground, the first and second configurations provide simple means of adjustment, such that the sweeping function and its effectiveness can also be height adapted by means of adjusting the wheels  7  and  8 . Also in this configuration, provision for a sweep collector is possible such that the direction of rotation will not need to be reversed and that extra protection to the user being hit by the swept material can also be provided. It is also possible to have a sweeper rolling against the direction of travel such that the ground material is always swept to the front. In this case, a sweep collector will not be necessary. In the case of such reverse transmission, the housing  23  is best recommended to adopt the snow throwing configuration i.e. facing front and open at the bottom as in the first operating configuration. 
     It can also be noticed that in particular through the turning of the housing  23 , every function of the combination device  1  can be optimally adapted to the corresponding task in question. The changing of work implements is enormously simplified through the special design of the transmission axle  21  on the one hand, and the gudgeoning pin  22  on the other, such that by their being pulled out, the tool implements can be inserted into the combination device  1  or the housing  23 . Tool changing takes place when the housing  23  is in its first operating configuration, as shown typically in  FIG. 1 . 
     Also it can be imagined that the front part of the combination device  1  with its assembly side plates  11  and  12  as well as the housing  23  can be used as a tool attachment for say a communal service vehicle. The simple retooling and the optimal setting up through the rotatable housing can also be advantageous. 
     While specific embodiments of the invention have been described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

Summary:
A combination device ( 1 ) is provided for carrying out various work tasks, such as cutting snow, mowing, scarifying, soil breaking or the like. The device includes a plurality of interchangeable work implements ( 60 ) tailored to the respective work task. A basic frame is provided in which the respective work implement ( 60 ) is accommodated and can be driven to rotate, and wherein the respectively installed work implement ( 60 ) is partially enclosed by a housing ( 23 ) extending parallel to the axis of rotation of the work implement. In order to tailor the combination device optimally to the respective work task, provision is made for the housing ( 23 ) to be able to rotate about an axis parallel to the axis of rotation of the respective work implement ( 60 ) and to be fastened in various operating positions corresponding to the respective work task.