Head for a dust vacuum cleaner

Abstract

It comprises a central hollow body ( 12 c ) including a central part ( 10 c ) of the open chamber connected to a negative pressure source and at least two side hollow bodies ( 12 a, 12 b ) joined to both sides of central hollow body ( 12 c ) by a hinge ( 13 ) which admits rotations with respect to a common axis substantially normal to the surface to be treated. The central part ( 10 c ) of the open chamber ( 10 c ) has an opening ( 14 ) at the hinging area ( 13 ) and side hollow bodies ( 12 a, 12 b ) comprise respective side parts ( 10 a, 10 b ) of the open chamber communicated with the said opening ( 14 ) of central part ( 10 c ) of the open geometry and comprises, by means of the said three side and central part ( 10 a, 10 b, 10 c ) of the open chamber the two side and central hinge ( 13 ) of the head.

1 . Head for dust vacuum cleaner of the kind comprising open chamber sucking means connected to a negative pressure source through at least a suitable duct, the said open chamber means are partly closed when the head is applied on the surface to be treated, delimiting at least a sucking front the head comprising at least two side hollow bodies ( 12   a,    12   b ) arranged on both sides of a hinge ( 13 ) allowing rotations with respect to a common angle which, with the head in working position is substantially normal to the said surface to be treated, the side hollow bodies ( 12   a,    12   b ) incorporating respective side parts ( 10   a,    10   b ) of the open chamber pneumatically with communicated the said negative pressure source so that the said sucking front has a variable geometry characterized in that the said hinge ( 13 ) is integrated in a central hollow body ( 12   c ) including a central part of open chamber ( 10   c ) connected to the said negative pressure source through an opening ( 14 ) located in the hinging area ( 13 ) a pneumatic communication of the side parts ( 10   a,    10   b ) of the open chamber being carried out with the said central part ( 10   c ) of the open chamber and opening ( 14 ) through the said hinge ( 13 ) in a range of relative positions wished and in that the said sucking front having a variable geometry is continuous in any of the said positions and comprises by means of the said three side and central parts ( 10   a,    10   b,    10   c ) of the open chamber the two side and central hinging areas ( 13 ) of the head.  
     
     
         2 . Head according to  claim 1 , characterized in that the said range of relative positions wished between the side and central parts ( 10   a,    10   b,    10   c ) of the open chamber is obtained by independent rotation of side hollow bodies ( 12   a,    12   b ) with respect to the central hollow body ( 12   c ) between a first position in which the said parts ( 10   a,    10   b,    10   c ) of the open chamber are substantially aligned, delimiting a straight crosswise sucking front and a second position in which the side parts ( 10   a,    10   b ) of the open chamber are forming between them an angle slightly smaller than a straight angle, with the said opening ( 14 ) substantially on the vertex, delimiting a point-shaped angular sucking front, adapted for angles and/or corners.  
     
     
         3 .- Head according to  claim 2 , characterized in that it comprises elastic means, such as one or more springs ( 11 ) connected between side hollow bodies ( 12   a,    12   b ) and central hollow body ( 12   c ) which tend to keep the set in the said first position.  
     
     
         4 .- Head according to  claim 3 , characterized in that it comprises means for locking the rotation of side hollow bodies ( 12   a,    12   b ) with respect to central hollow body ( 12   c ), the said locking means are releasable and in active situation they keep the set fixed in the said first position.  
     
     
         5 .- Head according to  claim 4 , characterized in that the said locking means are released by moving levers ( 9 ) which slightly protrude along the front parts of side hollow bodies ( 12   a,    12   b ) the said run of at least one of the said levers ( 9 ) can be caused by any hindrance which frontally contacts related side hollow body ( 12   a,    12   b ) in its forwards motion.  
     
     
         6 .- Head according to  claim 5 , characterized in that each of the said levers ( 9 ) is hinged by a swivel point and elastically loaded, including at a moving end a trigger ( 26 ) which hooks by the effect of the said elastic load a pawl ( 27 ) of central hollow body ( 12   c ), the said lever ( 9 ) when it is moved against the said elastic load, releases trigger ( 26 ) of pawl ( 27 ) allowing then the rotation of related side hollow body ( 12   a,    12   b ) to the second position.  
     
     
         7 .- Head according to  claim 2 , characterized in that each of the said side parts ( 10   a,    10   b ) of the open chamber, corresponding to each of the said side hollow bodies ( 12   a,    12   b ), comprises at least a longitudinal slot ( 16 ) which has a first end ( 16   a ) which communicates, at least at the said relative positions wished, through the said hinge ( 13 ) with the said opening ( 14 ) of the central part ( 10   c ) of the open chamber connected to the negative pressure source through central hollow body ( 12   c ) the bottoms of the said first ends ( 16   a ) of slots ( 16 ) remaining level with the bottom of the central part of open chamber ( 10   c ).  
     
     
         8 .- Head according to  claim 7 , characterized in that the said hinge ( 13 ) comprises a cylindric wall ( 17 ) arranged around opening ( 14 ) coaxial to hinge pin ( 13 ) the said cylindric wall ( 17 ) has interruptions, openings or undercuttings ( 18 ) through which the said communication of side parts ( 10   a,    10   b ) of the open chamber is carried out with the central part ( 10   c ) of the open chamber allowing the flow between them in the range of relative positions wished while the portions of cylindric wall ( 17 ) substantially close the flow in other directions.  
     
     
         9 .- Head according to  claim 8 , characterized in that the said cylindric wall additionally includes at least another interruption, opening or undercutting ( 19 ) allowing the flow therethrough between opening ( 14 ) and the area of the said vertex of the sucking front, at least when hollow bodies ( 12   a,    12   b,    12   c ) are in the said second position or close to it.  
     
     
         10 .- Head according to  claim 9 , characterized in that the said cylindric wall ( 17 ) is incorporated protruding from the periphery of a circular part ( 37 ) provided with a flat annular portion ( 38 ), and a recess on part of the bottom and side of which there is opening ( 14 ), circular part ( 37 ) is screwed to central hollow body ( 12   c ) keeping side hollow bodies ( 12   a  and  12   b ) in position and it collaborates in guiding the rotation thereof at same time that the said annular flat portion ( 38 ) covers the interfaces between the said parts avoiding the airflow and that dust penetrated within them.  
     
     
         11 .- Head according to  claim 1 , characterized in that central hollow body ( 12   c ) comprises, at its rear lower part, an additional sucking mouth ( 28 ) communicated with the central part ( 10   c ) of the open chamber through an opening provided with an obturator ( 29 ) which can optionally be opened or closed by the user depending on the kind of surface to be treated.  
     
     
         12 .- Head according to  claim 11 , characterized in that the said obturator ( 29 ) is associated to a mechanism of levers and cams connected to two foot-levers ( 30   a,    30   b ) accessible from outside for placing the said obturator at respectively open and closed positions.  
     
     
         13 .- Head according to  claim 7 , characterized in that the said longitudinal slot ( 16 ), which is at least one, of each of the said side hollow bodies ( 12   a,    12   b ) has a second end ( 16   b ) which ends at a side end distal of hinge ( 13 ) of related side hollow body ( 12   a,    12   b ).  
     
     
         14 .- Head according to  claim 7 , characterized in that hollow bodies ( 12   a,    12   b,    12   c ) comprise respective lower surfaces, mutually coplanar, in which related longitudinal slots ( 16 ) and opening ( 14 ) are provided, members protruding from the said lower surfaces for contacting the surface to be treated such as wheels ( 20 ,  20   a ), skids or sliding hemispheral stops which keep the said lower surfaces mutually coplanar substantially parallel to the said surface to be treated and at a predetermined height of this latter, so that the head is easily movable on the surface to be treated when it is applied when working on it.  
     
     
         15 .- Head, according to  claim 14 , characterized in that it comprises means for regulating the distance of protrusion of the said contacting members from the said lower surfaces, regulating with it the said predetermined height at least between two different levels, adapted for surfaces to be treated having different characteristics.  
     
     
         16 .- Head according to  claim 7 , characterized in that the said slots ( 16 ) width and deepness decrease when farther away they are from hinge ( 13 ).  
     
     
         17 .- Head according to  claim 7 , characterized in that the said slots ( 16 ) and/or opening ( 14 ) are flanked by the side opposite to the sucking front, by a protruding lip ( 15 ), of flexible and elastic material, such as rubber, which prevents a flow towards respective parts ( 10   a,    10   b,    10   c ) of the open chamber from the said side opposite to the sucking front.  
     
     
         18 .- Head according to  claim 1 , characterized in that hollow bodies ( 12   a,    12   b,    12   c ) are formed each by at least two parts which can be socketed and fastened to each other, obtained by plastic material injection moulding, a top shell ( 21 ) being provided associated to central hollow body ( 12   c ) for covering at least hinge ( 13 ), the said elastic means ( 11 ) and part of side hollow bodies ( 12   a,    12   b ) when they are at the said second position, through which shell ( 21 ) emerges a hinged coupling ( 22 ) of the central part ( 10   c ) of the open chamber with the said duct for connecting to the said negative pressure source, and protruding in addition through the said upper shell ( 21 ) there is foot-levers ( 30   a,    30   b ) connected through a lever and cam mechanism to an obturator ( 29 ) for opening and closing an additional sucking mouth ( 28 ) located at the rear lower part of central hollow body ( 12   c ) and communicated with the central part ( 10   c ) of the open chamber.  
     
     
         19 .- Head according to  claim 18 , characterized in that the said hinging coupling ( 22 ) comprises a cylinder or drum-shaped hollow body mounted so that it can rotate a given angle about the axis of the said cylinder or drum in a suitable housing of central hollow body, ( 12   c ) this hollow body comprising a side opening ( 24 ) communicating, at any of its position with open chamber ( 10   c ) and a crosswise coupling sleeve ( 25 ) which protrudes from an opposite side area, the said hollow body ( 22 ) being formed by two identical halves ( 22   a,    22   b ) coupled, each of them comprising one half of the cylinder or drum, one half of the opening ( 24 ) and one half of the sleeve ( 25 ).