Patent Publication Number: US-7909059-B2

Title: Mobile concrete pump having an articulated mast

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the National Stage of PCT/EP2007/054557 filed on May 11, 2007, which claims priority under 35 U.S.C. §119 of German Application No. 10 2006 031 257.0 filed on Jul. 6, 2006. The international application under PCT article 21(2) was not published in English. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a mobile concrete pump having a chassis, an articulated mast disposed on a substructure affixed to the chassis, serving as the carrier for a feed line, and having at least three mast arms, the first mast arm of which is articulated onto a rotating head that can be rotated about a vertical axis of the chassis, with a free end, by means of controlling a rotary drive, whereby the mast arms can be pivoted relative to the rotating head and relative to an adjacent mast arm, in each instance, about horizontal articulation axes, by means of controlling related articulation drives, and having two front and two rear support booms, disposed on the substructure affixed to the chassis, which booms can be moved from a travel position into a support position, if necessary partially, each has a telescoping support leg, and can be supported on a substratum, raising the chassis. 
     The support booms supported on the substratum with their support legs delimit a support quadrangle, when the chassis is raised, having four tipping edges that extend between the adjacent corners, and the center of gravity of the system is not allowed to go beyond these edges, towards the outside, during movements of the mast arm. When the support booms are fully extended and supported, a rotation by the fully unfolded and horizontally oriented mast arm, of 360° by its rotating head, is usually possible, without any risk of tipping. Furthermore, it is fundamentally known, particularly in the case of narrow construction sites, that the support booms are extended and supported only on one side of the chassis, while they are supported on the substratum in their folded-in position on the other side. In this case, there is a restricted work range of the mast towards the side supported by the extended support booms. In the case of telescoping front support legs and pivoting rear support legs, the rotation angle range of the mast arm between the position pointing to the rear, parallel to the chassis, and its position pointing forward amounts to approximately 130°. This restriction in the rotation angle range in the case of narrow support is constantly felt to be a disadvantage in practice. 
     Proceeding from this, the invention is based on the task of improving the known mobile concrete pump having an articulated mast and support booms, of the type indicated initially, to the effect that even in the case of a restricted support position, as compared with full support, the maneuvering range of the articulated mast can be improved. 
     SUMMARY OF THE INVENTION 
     To accomplish this task, the combination of characteristics indicated in claim  1  is proposed. Advantageous embodiments or further developments of the invention are evident from the dependent claims. 
     The solution according to the invention proceeds from the idea that each support boom has a support position close to the chassis and at least one support position away from the chassis, which positions can be freely selected for the four support booms, forming defined support configurations. With every support configuration, only those mast arm movements are allowed at which the center of gravity of the machine moves within the tipping quadrangle, in other words within the tipping edges, without the risk of improper operation. In order to achieve this, it is proposed, according to the invention, that a control device for the mast arm movement is provided, which has a software routine or restriction circuit that responds to the support configuration selected, which restricts the pivot angle range of the first mast arm about its articulation axis, and restricts a related rotation angle range of the rotating head about its vertical axis, in accordance with the selected support configuration. 
     Another advantageous embodiment of the invention provides that at least one of the mast arms consists of two telescope segments that can be displaced in the direction of the arm. It is practical, in this connection, if the first and/or the last mast arm is composed of two telescope segments. In this case, the software routine according to the invention or the restriction circuit restricts the pivot range of the first mast arm and/or the telescoping path of the first and/or last mast arm, as well as a related rotation angle range of the rotating head about its vertical axis, in accordance with the support configuration selected. 
     In advantageous manner, for this purpose, a selection switch having multiple switch positions that correspond to the different support configurations is provided, whereby the control device for the mast arm movement responds to the switching positions of the selection switch. 
     An expansion in the rotation angle range can be achieved, in the case of articulated masts having at least four mast arms, in that the control device for the mast arm movement has a subroutine or restriction circuit that responds to the support configuration selected, which restricts not only the pivot angle of the first mast arm, but also the pivot angle of the second mast arm about its articulation axis. Analogously, a further expansion in the case of articulated masts having at least five mast arms is possible, if the control device for the mast arm movement has a subroutine or restriction circuit that responds to the support configuration selected, which also restricts the pivot angle of the third mast arm about its articulation axis. It is practical if the restriction circuit that is alternatively provided has at least one end switch. 
     In practical use, the invention is particularly seen as being that the control device for the mast arm movement has a locking device that locks the articulation drive of the first mast arm in its position oriented essentially parallel to the vertical axis. The expansions indicated above, for mast arms having at least four and five arms, consist in the fact that the control device for the mast arm movement has a locking device that locks the articulation drive of the second mast arm, and, if applicable, also of the third mast arm, in their position aligned with the first mast arm. It is practical if the locking device that is alternatively provided has at least one end switch. 
     Using the measures according to the invention, the result is achieved that by locking the first mast arm and, if applicable, any other mast arms, in their orientation parallel to the vertical chassis axis, a reduction in the center of gravity circles during rotation of the articulated mast about the vertical axis results, which yields an expanded work range in the angle of rotation even in the case of restricted support configurations, which range can amount to as much as 360° in the case of appropriate coordination between support configuration and arm locking. 
     Another advantageous embodiment of the invention provides that the control device has a software routine or a restriction circuit that responds to the support configuration that was input, and to the pivot angle of the first mast arm, and selects the rotation range of the rotating head in accordance with these data. A further improvement in this regard is achieved if the software routine or the restriction circuit additionally responds to the pivot angle of the second mast arm when the first mast arm is oriented essentially parallel to the vertical axis, and selects the rotation range of the rotating head for this. A further improvement is achieved if the software routine or the restriction circuit additionally responds to the pivot angle of the third mast arm when the first and second mast arm are oriented essentially parallel to the vertical axis, and selects the rotation range of the rotating head for this. It is practical if the restriction circuit that is alternatively provided has at least one end switch. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following, the invention will be explained in greater detail using exemplary embodiments shown schematically in the drawing. This shows: 
         FIG. 1   a  to  c  a schematic relating to determining the work range of the mast movement of a mobile concrete pump in the case of three different support and mast arm configurations; 
         FIG. 2  a selection switch for selecting different support configurations of a mobile concrete pump; 
         FIG. 3   a  a flow chart of a software routine for restricting the work range in the case of narrow support on one side; 
         FIG. 3   b  a flow chart of a software routine for establishing the work range in the case of support of the support legs in the non-extended state of the support booms, close to the chassis. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The mobile concrete pump shown in  FIG. 1   a  to  c  comprises a chassis  10 , a four-arm articulated mast  14  disposed on a substructure  12  affixed to the chassis, serving as the carrier for a feed line, as well as two front support booms  16 ′,  16 ″ and two rear support booms  18 ′,  18 ″. In the case of the exemplary embodiment shown, the articulated mast  14  has four mast arms  1 ,  2 ,  3 ,  4 . In this connection, the first mast arm  1  is articulated onto a rotating head  24  that can be rotated about a vertical axis  22  of the chassis  10 , with its one end  20 , by means of controlling a rotary drive. For the remainder, the mast arms  1 ,  2 ,  3 ,  4  can be pivoted relative to the rotating head  24  and relative to an adjacent mast arm, in each instance, about horizontal articulation axes A, B, C, D, by means of controlling related articulation drives. The last mast arm  4  carries an end hose  26  at its free end, which hose is connected with the feed line, not shown. 
     The front support booms  16 ′,  16 ″ can be telescoped, relative to the substructure  12  affixed to the chassis, from a retracted travel position into an extended support position that points forward at a slant. The two rear support booms  18 ′,  18 ″ can be pivoted about an axis  28  fixed in place on the chassis, from a travel position oriented essentially parallel to the chassis into a support position that points backward at a slant. Furthermore, all the support booms  16 ′,  16 ″,  18 ′,  18 ″ have a telescoping support leg  30 , with which they can be supported on a substratum  32 , raising the chassis  10 . In the rear region of the chassis  10 , there is a hydraulically operated thick-matter pump  34 , which transports the liquid concrete filled in by way of an application container  36  along the chassis and the articulated mast  14  to the end hose  26 , by way of the feed line  38 . 
     Depending on the space requirements at the construction site, the support booms can optionally be supported in an inner support position close to the chassis, or an outer support position away from the chassis, with their support legs on the substratum, forming different extension configurations. 
     In the case of the exemplary embodiment according to  FIG. 2 , six support configurations that can be selected by way of a selection switch  40  are provided, namely one full support V, one narrow support SL (left) and SR (right), in each instance, one Y support YL (left) and YR (right), in each instance, and one near support N. 
     In this connection, the full support V is selected in such a way that the mast charged with liquid concrete can be rotated, in the extended horizontal position, about the vertical vehicle axis  22 , in a rotation range of 360° of the rotating head  24 , without any risk of tipping. 
     In the case of the narrow supports SL and SR according to  FIG. 2 , the permissible work range for the mast movement towards the support side is restricted to a defined rotation angle range. The permissible rotation range of the articulated mast in the case of a fully extended articulated mast, also at the mast arm  1 , amounts to between 0° and 130° for the support configuration SL shown in  FIG. 1   a . This angle range can be expanded to 180° in the case of the support configuration SL in question if the first mast arm  1  is locked in place in its position shown in  FIG. 1 , essentially parallel to the vertical axis  22 . 
     A further increase in the permissible work range is achieved, according to  FIG. 1   b , in that the front right support boom  16 ″ is also extended, forming the support configuration YL. In this case, the rotation angle range with the articulated mast extended amounts to 230° at the first mast arm, as well. It can be extended slightly further if, in addition, as shown in  FIG. 1   a , the first mast arm  1  is locked in its vertical position. 
     In  FIG. 1   c , the rotation range for the case of the support configuration N (near position) is shown, in which all four support booms  16 ′,  16 ″,  18 ′,  18 ″ are supported with their support legs  30  on the substratum  32  in an inner position, close to the chassis. In this case, stable support is obtained only if not only the first mast arm  1  but also the second mast arm  2  are locked in their vertical position. In this case, the rotation range amounts to 360°, with a correspondingly reduced work radius. 
     The mobile concrete pump comprises a control device for the mast arm movement, which responds to the switching positions of the selection switch  40  for the various support configurations. The control device is computer-assisted. The two flow charts according to  FIGS. 3   a  and  b  are intended to illustrate the functioning of the control device in monitoring the mast arm movement. 
     The flow chart according to  FIG. 3   a  shows the work method of a software routine of the control device for the case of one of the narrow supports LS and SR, which are indicated there with the abbreviation “OSS” [one-sided support]. If the pump operator at the construction site decides, when extending the support legs in accordance with the local conditions, that a narrow support is required (OSS required?), a restricted work range occurs as compared with the work range of 360° that is decisive for full support. For this purpose, the related arm configuration (here, SL or SR) must first be selected, by way of the selection switch  40 . As long as the mast arm  1  has an articulation angle ≦88° at the articulation axis A, the work range is restricted to 130° by way of the control device. A larger work range can be set in that the arm  1  is brought into its position essentially parallel to the vertical axis (angle about the articulation axis &gt;88°). There, the arm can be locked in place, and thus the work range can be expanded to 180° (cf. also  FIG. 1   a ). The work ranges of 130° and 180°, respectively, must also be taken into consideration when folding the articulated mast back in. 
     The flow chart according to  FIG. 3   b  illustrates the method of procedure when using the arm configuration N ( FIG. 2 ), in other words if all the support booms are supported on the substratum in their inner position, close to the chassis (cf. also  FIG. 1   c  in this regard). 
     When the support legs are supported in the work configuration N, and after pre-selection of the selection switch  40  to the position N, at first the rotating head is locked outside of the angle range 5° to 35°. If, in the case of n=4 mast arms, the first and second mast arm (n−2=2) are brought into the vertical position (&gt;88°), the two arms  1  and  2  can be locked, and the rotation range can be expanded to 360°. Release of the first or second arm is only possible if the rotating head with the articulated mast is oriented essentially in the longitudinal direction of the vehicle, in the range of 0 to 5° and 35° to 360°. In this position the articulated mast can also be folded back into its travel position. 
     Fundamentally, it is possible that at least one of the mast arms consists of two telescope segments that can be displaced in the longitudinal direction of the arm. In this connection, the first mast arm or the last mast arm, for example, can be configured as a telescope arm. In this case, the software routine or the movement circuit restricts the pivot range of the first mast arm about the articulation axis A and/or the telescoping movement of the first and/or last mast arm, as well as a related rotation angle range of the rotating head about its vertical axis, in accordance with the selected support configuration. 
     In summary, the following should be stated: The invention relates to a mobile concrete pump having an articulated mast  14  that serves as a carrier for a feed line, and having two front and two rear support booms  16 ′,  16 ″,  18 ′,  18 ″ that can be moved from a travel position into a support position, each having a telescoping support leg  30 , which booms can be supported on a substratum  32 . According to the invention, each support boom has an inner support position close to the chassis, and at least one outer support position away from the chassis, which positions can be freely selected for the four support booms, forming defined support configurations V, SL, SR, YL, YR, N. Furthermore, a control device for the mast arm movement is provided, which has a software routine that responds to the support configuration selected, which restricts the pivot angle of the first mast arm  1  about its articulation axis A, and restricts a related rotation angle range of the rotating head  24  about the vertical axis  22 , in accordance with the selected support configuration.