Abstract:
A support foot ( 1 ) for supporting a free standing structure on a flat roof includes a holding means ( 34; 62; 63 ) for holding a profiled section ( 40 ) to which other parts of said structure can be mounted. The support foot comprises a base part ( 2 ) with a guiding structure ( 22 ). The support foot ( 1 ) furthermore comprises a skid part ( 3; 6 ), which includes the holding means ( 34; 62; 63 ) for the profiled section ( 40 ) and which is slidably mounted on the guiding structure ( 22 ) of the base part ( 2 ) so as to position the holding means ( 34; 62 ,-  63 ) for the profiled section ( 40 ) in a desired angular position allowing to compensate for a possible slope of the flat roof. The support foot ( 1 ) also includes securing means for securing the skid part ( 3, 6 ) in said desired angular position on the base part ( 2 ).

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a roof support system. In particular the present invention relates to a roof support foot for a free standing structure on a roof. 
     It is known to place installations like climate installations, solar panels, walkways, piping etc. on flat roofs. These flat roofs are often provided with an insulation layer with a moisture proof and vaportight sheet, e.g. from bitumen. These insulation layers and sheets are not made to carry high loads. Furthermore, it is desirable to prevent as much as possible piercing the sheets for anchoring a structure to the roof, because the piercings may cause problems with water/moisture resistance of the roof. 
     To overcome the problem of piercing it is known in the art to place installations free standing on a roof. On the market can be found for example a support system under the name “Big Foot Systems”, wherein a support foot is standing free on a roof and the support foot has a socket in which a profiled section, for example a hollow profile with a square cross section, can be inserted. The profiled section extends in a direction perpendicular to the bottom surface of the support foot. 
     Although the known support system prevents that the insulation layer and moisture proof sheet has to be pierced, it is in practise not fully satisfactory. 
     In practise most flat roofs have a slope in view of the drainage of water. This slope must be sufficient and will most of the time have an angle of inclination in the range 2°-7° with respect to the horizontal. The known support system placed on a flat roof with a certain slope will result in upright profiles not standing totally vertical. It is obvious that from a practical and constructional point of view, this is disadvantageous. 
     The present invention has for an object to provide an improved support system for free standing structures on a flat roof. 
     SUMMARY OF THE INVENTION 
     This object is achieved by a support foot for supporting a free standing structure on a flat roof, includes a holding means for holding a profiled section to which other parts of said structure can be mounted. The support foot comprises a base part with a guiding structure. The support foot also comprises a skid part, which includes the holding means for the profiled section and which is slidably mounted on the guiding structure of the base part so as to position the profiled section in a desired angular position allowing to compensate for a possible slope of the flat roof. The support foot furthermore includes securing means for securing the skid part in said desired angular position on the base part. 
     With the support foot according to the invention, which is placed on a flat roof with an inclination, the base part essentially has an inclined position due to the slope of the flat roof. The position of the skid part on the guiding structure of the base part can be adjusted such that the profiled section can be positioned in a vertical or horizontal direction, notwithstanding the fact that the base part is resting on an inclined roof surface. Thus, a support foot is provided which can be used on many different flat roofs and which can be adjusted easily on site to the circumstances. 
     In a preferred embodiment the guiding structure comprises an arched path such that the profiled section received in the skid part can be positioned in different inclinations, by positioning the skid part on different positions on the arched path. 
     In a further preferred embodiment the guiding structure has a first arched sliding surface, and the skid part has a second arched sliding surface which is complementary to the first arched sliding surface and engages said first arched sliding surface, wherein preferably the first arched sliding surface is convex and the second arched sliding surface is concave. Alternatively it is also possible to have a concave first arched sliding surface and a convex second arched sliding surface. 
     In another preferred embodiment the arched path on the base part is flanked by two side walls for preventing movement of the skid part in a direction transverse to the arched path. In this way a simple sideways support for the skid part is provided, which provides additional guiding of the skid part on the arched path. 
     In one preferred embodiment, the securing means for securing the skid part in said desired angular position on the base part, comprise tensioning means for clamping the skid part to the guiding structure of the base part. 
     In a further preferred embodiment, the skid part has at least one bore and the guiding structure has a slotted hole, the securing means comprising at least one male tensioning member, preferably a bolt, which extends through said bore and through said slotted hole, the slotted hole allowing the skid part with the male tensioning member to be positioned in the desired position on the guiding structure, the securing means furthermore comprising a female tensioning member, preferably including a nut, for cooperating with the male tensioning member so as to secure the skid part in said desired position on the base part. This provides an easy to use and robust securement of the skid part on the base part. 
     Preferably the guiding structure, on the side opposite the side where the skid part engages, at least at the location of the slotted hole has a counter surface on which the female tensioning member engages. Preferably the counter surface is provided with ribs, which provides an even better grip of the female tensioning member on the base part. The female tensioning member may comprise a clamping member which engages the counter surface, as well as a nut for tensioning the clamping member against the counter surface, wherein preferably the clamping member has a cavity in which the nut is accommodated. In a further preferred embodiment the clamping member has ribs which engage the ribs on the counter surface whereby a secure connection of the skid part on the base part is ensured. 
     In one preferred embodiment the holding means for the profiled section comprises at least one socket in which an end of a profiled section is insertable, such that the profiled section is held in an upstanding fashion. Preferably an insert element is provided which is provided in the socket and in which the end portion of the profiled section is inserted, which insert element in a pre-mounting state, in which no profiled section end is inserted, is rotatable around its centre axis to a plurality of orientations within the socket, and which insert element is held in position in a mounted state, in which the end portion of the profiled section is inserted, by clamping. 
     The insert element may be rotatable to discrete orientations or the insert element may be rotatable in any orientation. In this way an upstanding profiled section may be oriented in any direction such that a structure placed on the roof can extend in any direction on the roof, independently from the direction of the slope. 
     In another preferred embodiment the holding means comprise at least one receiving means in which a part of the length of the profiled section is supported, such that the profiled section is held in a lying fashion, preferably horizontal. 
     In a preferred embodiment the base part is provided with male or female positioning means for positioning ballast elements on the base part, which ballast elements are provided with complementary male and/or female positioning means. In this way one or more ballast blocks may be placed in a well defined and solid manner on top of the base part. 
     The support foot may include an anti-slip and/or anti-vibration mat which is positioned on the underside of the base part. The base part may be provided with male and/or female positioning means and the anti-slip and/or anti-vibration mat may be provided with female and or male positioning means engaging the male and/or female positioning means of the base part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be elucidated in more detail in the following description of preferred embodiments with reference to the drawing. 
         FIG. 1  shows in a perspective view a base part of a preferred embodiment of a support foot according to the invention; 
         FIG. 2  shows in a perspective view a skid part of a preferred embodiment of a support foot according to the invention; 
         FIG. 3 a    shows in a perspective view from above a preferred embodiment of the support foot wherein the skid part of  FIG. 2  is mounted on the base part of  FIG. 1 ; 
         FIG. 3 b    shows a perspective view from below the support foot of  FIG. 3   a;    
         FIG. 4  shows the support foot of  FIG. 3  in which a profiled section is held in an upstanding manner; 
         FIG. 5  shows in perspective view another skid part of a preferred embodiment of the support foot according to the invention; 
         FIG. 6  shows a preferred embodiment of the support foot wherein the skid part of  FIG. 5  is mounted on the base part of  FIG. 1 ; 
         FIG. 7  shows a front view of a support foot of  FIG. 6  with a profile rail placed in it; 
         FIG. 8  shows an anti-vibration mat for the support foot of the present invention; 
         FIG. 9  shows an insert element for use with the skid part of  FIG. 2  or the socket in  FIG. 7 ; 
         FIG. 10  shows in a sectional view securing means securing the skid part of  FIG. 2  to the base part of  FIG. 1 ; and 
         FIG. 11  shows a support foot with ballast blocks stacked on it. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 3 a    is shown a support foot  1  comprising a base part  2  and a skid part  3 . Both parts  2 ,  3  are preferably made of plastic by injection moulding, but one or both parts  2 ,  3  may also be made of another material for example steel or another metal. The base part  2  is shown separately in  FIG. 1  and comprises a base plate  21 , which in the shown example is substantially square with rounded corners, but which may have any other suitable shape, such as circular, triangular, polygonal, etc. The base plate  21  has a top side, which is visible in  FIG. 1 , and a bottom side opposite thereof, which is visible in  FIG. 3   b.    
     In a middle portion on the top side of the base plate  21  is arranged a guiding structure  22 , including longitudinal webs  23  and transverse webs  24 . The longitudinal webs  23  have a curved upper edge. The web arrangement is flanked by two side walls  26 . The side walls  26  extend in an upward direction beyond the upper edges of the webs  23 ,  24 . The side walls  26  have in the specific embodiment shown a curved upper edge, but this is not necessary. In the middle region of the guiding structure  22  an arched surface portion  25  is provided. The upper edges of the webs  23 ,  24  and the arched surface portion  25  constitute an arched sliding surface. In the arched surface portion  25  is provided a longitudinal slot  27 . On the bottom side of the arched surface portion  25  is provided a cavity  210  which is open on the bottom side and which is visible in  FIG. 3   b.    
     From the side walls  26  are extending stiffening ribs  28  on the upper side of the base plate  21  towards the edge of the base plate  21 . Instead of the stiffening ribs  28 , also other means for stiffening the structure my be provided. 
     Near the four corners of the base plate  21  an upwardly extending positioning means  29  is arranged on the base plate  21 . The positioning means  29  are hollow and open on the bottom side of the base plate  21  as can be seen in  FIG. 3   b.    
     In  FIG. 2  is shown a skid part  3 . The skid part  3  essentially comprises an arched body  31  with a concave bottom surface  32  and a convex upper surface  33 . The concave bottom surface  32  constitutes a sliding surface which engages the arched sliding surface of the base part  2  as can be seen in  FIG. 3   a.    
     On the upper surface  33  in the middle is provided a cylindrical socket  34  which in the shown embodiment is integral with the arched body  31 . From the outside of the socket  34  on the upper surface  31  are extending stiffening ribs  35  towards the edge of the arched body  31 . It is also conceivable to have no stiffening means or other stiffening means than the ribs  35  shown in the figure. 
     The socket is cylindrical with a circular cross-section, but may also have another shape. For example a socket with a square cross-section is conceivable. Also a polygonal shape is conceivable. 
     In front of the cylindrical socket  34  on the longitudinal axis is provided a bore  36 . A same bore  36  is provided on the diametrical opposite side of the socket  34 . 
     In  FIG. 3 a    is shown that the skid part  3  is mounted on the guiding structure  22  of the base part  2 . 
     On the underside of the base part  2  may be provided a vibration isolating anti-slip mat  8 , which is shown separately in  FIG. 8 . The anti-slip mat  8  is made of a suitable isolating material, for example rubber. In the shown embodiment the mat  8  has substantially the same contour as the base plate  21  of the base part  2  and may be ribbed on the upper side as is shown in  FIG. 8 . However the mat may also have another shape as is shown here. In the corner regions are provided upwardly extending male positioning means  81 , which mate with the female positioning means  29  on the bottom side of the base plate  21  of the base part  2 . 
     In  FIG. 3 a    the skid part  3  is mounted in a middle position on the guiding structure  22 . Thus the centre axis of the socket  34  of the skid part  3  extends perpendicular with respect to the base plate  21  of the base part  2 . The skid part  3  can slide on the guiding structure  22  in the direction illustrated by the double arrow indicated with reference numeral  39 . 
     In the socket  34  is inserted an insert element  9 , which is separately shown in  FIG. 9 . The insert element  9  in the shown embodiment has a body  91  with a substantially square cross section, wherein the body  91  has four slotted side walls  92 . The outer dimensions of the body  91  are such that the body  91  can be positioned in any orientation within the cylindrical socket  34 . The insert element  9  has an open upper end  93  through which a profiled section, for example a C-profile or strut profile  40  can be inserted as is shown in  FIG. 4 . Through the insertion of the end portion of the profiled section  40  in the insert element, the insert element  9  is clamped against the inner side of the socket  34  and thereby secured in position. 
     In  FIG. 3 a    is shown how the insert element  9  is oriented such that the side walls  92  extend substantially parallel to the sliding direction  39  (see  FIG. 3 a   ) of the skid part  3  on the guiding structure  22 . However, as mentioned before, insert element  9  can be rotated through 360° in a pre-mounting state when no profiled section is inserted. An arbitrary orientation of the insert element  9 , different from the one in  FIG. 3A  is shown in  FIG. 4 . 
     If the socket has for example a square cross-section, the profiled section with the insert element can be positioned in four different angular positions. 
     By sliding the skid part  3  on the guiding structure  22  a certain inclination of the socket  34  with respect to the base plate  21  can be selected. This is done to compensate for the slope of the flat roof on which the support foot is placed, such that the profiled section  40  extends in the vertical direction. When a suitable position of the skid part  3  on the guiding structure  22  is selected, the skid part  3  can be secured to the guide structure  22  of the base part  2  as is illustrated in  FIG. 10 . 
     In  FIG. 10  is shown how a bolt  50  extends through each of the bores  36  in the skid part  3 . Each bolt  50  has a bolt head  51  which rests on the upper surface of the skid part  3 . The bolts  50  extend through the slot  27 . At the opposite end of the bolt  50  a clamping element  52  is provided with a nut  53  incorporated in it. The upper side of the clamping element  52  engages the bottom side of the arched surface portion  25 , which bottom side constitutes a counter surface for the clamping action securing the skid part  3  to the base part  2 . The counter surface is indicated by reference numeral  25   a  and is in the shown embodiment provided with ribs. The upper side of the clamping element  52  is also provided with ribs, such that upon tightening the nut  53  on the bolt  50 , the clamping element  52  firmly engages the counter surface  25   a  and a good securement is assured. 
     Furthermore, the clamping element  52  has a width that corresponds essentially to the width of the cavity  210 . Hereby the clamping element  52  with the nut  53  in it can not rotate with respect to the base part  2 . Thus the clamping element  52  can be tensioned against the counter surface  25   a  by simply rotating the bolt  50  at the bolt head  51 . Thus the skid part can be secured on the guiding structure  22  of the base part  2  between the extreme positions on the arched surface, which might be a 7° angle with respect to the middle position. The maximum angle might however also be smaller or greater. 
     In  FIG. 6  is shown a different embodiment of a support foot according to the invention. In this embodiment the same base part  2  is used as is used in the previously described embodiment, thus the base part that is shown in  FIG. 1 . 
     The support foot of  FIG. 6  has a skid part  6  which is shown separately in  FIG. 6 . This skid part  6  is adapted to receive a profiled section  40 , in this case a strut rail which extends horizontally (see  FIG. 7 ) rather than in an upstanding (vertical) fashion which was described in the previously described embodiment. The functionality of the skid part  6  is the same as the skid part  3 , but the difference is that it has no socket but a flat support surface  62  for supporting one side of a profiled section, for example a C-profile. The support surface  62  is somewhat countersunk in the body  61  of the skid part  6 . In the support surface  62  are provided one or more bores  63  through which a bolt can be run to fix the C-rail to the skid part  6 . Also bores  64  are provided through which bolts can be which extend through the slot  27  in the guiding structure  22  of the base part, to secure the skid part  6  in a certain position similar to the previously described embodiment. 
     In  FIG. 11  is shown a support foot as is shown in  FIG. 4 . As can be seen the skid part  3  has been fixed under a certain angle with respect to the middle position of the skid part  3 . In this way the slope of a flat roof can be compensated such that the upstanding profiled section  40  (not shown in this figure) extends in a vertical direction. On the base plate  21  of the base part  2  are arranged two parallel ballast blocks  11   a  which near the respective ends are provided with holes  12 . The holes  12  are positioned over the male positioning means  29  on the base plate  21 , such that the ballast blocks  11   a  are well held in position on the base plate. 
     On the upper side of the ballast blocks  11   a  are provided upwardly extending protrusions  13 . In a transverse direction are placed two parallel ballast blocks  11   b . These ballast blocks are the same as the ballast blocks  11   a  and the protrusions  13  of the lower ballast blocks  11   a  are inserted in the holes  12  of the upper ballast blocks  11   b . Thus four ballast blocks can be positioned in a well defined and solid manner on a support foot in order to keep it standing firmly on a roof surface, even if the roof is inclined and the structure that is supported by the support foot applies some kind of tilting moment on the foot. Of course also more ballast blocks  11   a ,  11   b  can be stacked.