Patent Publication Number: US-6668497-B1

Title: Concrete placing boom adapter

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a support structure for supporting a concrete placing boom at a work site. More specifically, the present invention relates to a support structure that includes an adapter that is removably attachable to a support mast and receives the concrete placing boom such that a single adapter can be used with multiple support masts. 
     Currently, concrete placing booms are used at large work sites, such as in the construction of a multi-floored building, for placing concrete in hard to access locations. Typically, the concrete placing boom is mounted to a support structure that extends above the working surface such that concrete can be supplied from above without requiring heavy hoses to be dragged over the deck, reinforcing and post tensioning cables. 
     In a large work site, multiple support masts or towers are constructed such that the concrete placing boom can be moved from one support tower to the next in order to provide the required coverage area for the structure being created. In currently available support structures for the concrete placing boom, an adapter is integrally formed with each of the towers or support masts. Each adapter is sized to receive a pedestal formed on the concrete placing boom. An overhead crane is used to move the concrete placing boom and pedestal above the adapter until the concrete placing boom can be lowered into contact with the adapter. Once in contact with the adapter integrally formed with the support mast, the pedestal can be secured to the adapter and support mast. 
     In several currently available support systems, each of the support masts or towers includes its own adapter secured to the tower. Since each adapter is a large and heavy structure, it is possible that several adapters located at each work site are not being used at any given time. 
     The support masts or towers in the currently available systems include numerous projections used to secure the mast within a concrete floor opening. However, the projections can contact the floor opening and damage the opening when the support mast is moved from one floor to another. Thus, additional care must be taken when moving the prior art support structure from one location to another, which increases the time needed to move the equipment. 
     Therefore, a need exists for a support structure for a concrete placing boom in which an adapter is removably attachable to each of the support masts or towers positioned at the work site. Further, a need exists for an adapter that can be removed from one of the support masts and attached to another support mast through a simple mounting arrangement. Additionally, a need exists for an adapter that is received upon the support mast and includes a self-aligning feature to ensure the proper connection of the adapter to the support mast. Further, a need exists for a support mast that does not include external projection to decrease the care required to move the support mast between floors of a building being constructed. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a support structure for supporting a concrete placing boom above a work site such that the concrete placing boom can supply a flow of concrete to a particular work position. The support structure of the present invention includes a plurality of individual support masts positioned about the work site. Each of the support masts extends above and is supported by a support surface. For example, each support mast can be supported on and by a lower floor of a building being constructed. 
     Each support mast is a generally cylindrical structure having an outer wall defining a generally hollow interior. The outer wall of the support mast has an outer surface that is generally devoid of any external projections. The smooth outer surface of the support mast allows the mast to be efficiently manufactured and moved longitudinally with respect to an opening formed in the support surface. 
     The support mast is closed at its top end by a top plate. The top plate of each support mast includes a central guide opening that aids in locating the center of the support mast. 
     The support structure of the present invention further includes an adapter that is removably mountable to any one of the plurality of support masts positioned around the work site. The adapter includes a boom attachment portion configured to receive the mounting pedestal of the concrete placing boom and a mast receiving portion that is configured to receive the respective support mast. In this manner, the adapter can be removably attached to both the concrete placing boom and the support mast. Thus, only one adapter is required for the entire support structure of the invention. 
     The boom attachment portion of the adapter includes a top support plate mounted to the top end of the adapter. The top support plate provides the required support for a series of inner and outer lugs. The inner and outer lugs are spaced from each other to receive depending ears formed on the pedestal of the concrete placing boom. When the concrete placing boom is lowered onto the adapter, the ears of the pedestal are positioned between one of the inner lugs and one of the outer lugs and an attachment bolt secures the adapter to the pedestal. 
     The mast receiving portion of the adapter is defined at its top end by a mast support plate that is positioned within the interior of the adapter. The mast support plate is secured to the inner surface of the cylindrical wall forming the body portion of the adapter. When the adapter is lowered into contact with the mast, the top end of the mast contacts the mast support plate such that the adapter is supported on the mast by the mast support plate. 
     The mast support plate includes a guide pin that is sized to fit into the mast receiving receptacle. The guide pin includes a tapered lower surface that is sized to be received within the central guide opening formed on the top end of the mast. The interaction between the guide pin and the central guide opening formed in the top plate of the mast aids in guiding the proper alignment between the adapter and the mast. 
     Once the adapter is positioned on the respective mast, a pressure coupling contained on the mast receiving portion of the adapter is tightened to secure the adapter to the mast. In the preferred embodiment of the invention, the pressure coupling includes a plurality of adjustment screws that can be tightened into contact with the outer surface of the mast. Preferably, a strengthening plate is mounted within the mast and aligned with the contact points between the pressure coupling and the masts. In this manner, the strengthening plate provides further support for the outer wall of the mast. 
     The removable adapter of the present invention allows the adapter to be removed from one support mast and reinstalled on a second support mast. Thus, only a single adapter is required for a work site having multiple support masts. Since the adapter is a substantial structure, the inclusion of only one adapter in the support structure of the invention significantly reduces the cost of the overall system. 
     Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate the best mode presently contemplated of carrying out the invention. 
     In the drawings: 
     FIG. 1 is a side view of the concrete placing boom and support structure for supporting boom on a support mast; 
     FIG. 2 is a side view illustrating the removal of the concrete placing boom and pedestal froze adapter that is connected to the support mast; 
     FIG. 3 is a section view illustrating the removal of the adapter from the support mast; 
     FIG. 4 is a section view taken along line  4 — 4  of FIG. 2 illustrating the interconnection between e adapter and support mast of the support structure of the invention; 
     FIG. 5 is a top view taken along line  5 — 5  of FIG. 4 illustrating the top support plate of the adapter; 
     FIG. 6 is a section view taken along line  6 — 6  of FIG. 4; and 
     FIG. 7 is a section view taken along line  7 — 7  illustrating the pressure coupling between the adapter and support mast. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first to FIG. 1, there is shown a concrete placing boom  10  that is used to deliver a supply of concrete to a remote location. The concrete placing boom  10  includes a boom arm  12  consisting of four separate sections  14 ,  16  and  18 . The boom arm  12  is rotatable about a pedestal  20  and can be raised, lowered and extended to adjust the delivery point of concrete. In the preferred embodiment of the invention, the concrete placing boom is available from Putzmeister America of Sturtevant, Wis., as Model No. MXR 34/38. The concrete placing boom  10  has a horizontal reach of approximately 111 feet from the pedestal  20 . 
     In the embodiment of the invention illustrated in FIG. 1, the concrete placing boom  10  has a weight of approximately 6.5 tons, while the pedestal  20  weighs approximately 2.5 tons. Thus, the combined concrete placing boom  10  and pedestal  20  have a total weight close to 9 tons. Because of this weight, the concrete placing boom  10  and pedestal  20  must be securely supported at a desired location at a work site and can only be moved by heavy lifting equipment. 
     As illustrated in FIG. 1, the concrete placing boom  10  and pedestal  20  are mounted to a support mast  22  by an adapter  24 . As will be discussed in greater detail below, the adapter  24  includes a boom attachment portion  23  and a mast receiving portion  25  that allow the adapter to be removably attachable to both the support mast  22  and the pedestal  20 . Although not shown in the drawings, multiple support masts  22  can be positioned about a work site and the concrete placing boom  10  and adapter  24  can be transferred between the plurality of support masts  22  in order to provide the required coverage for the concrete structure being formed. 
     As can be seen in FIGS. 1 and 3, the support mast  22  is formed by a cylindrical outer wall  26  that defines a generally hollow open interior  28 . In the embodiment of the invention illustrated, the outer wall  26  defines a cylinder having an outer diameter of approximately 81 centimeters. 
     As illustrated in FIG. 1, the support mast  22  is supported on a floor slab  30  by a floor bracket  32  and a plurality of individual wedges  34 . In the preferred embodiment of the invention, the mast  22  includes a plurality of locking apertures  36  that are formed near the bottom end  38  of the support mast. The locking apertures  36  are each sized to receive a cross pin (not shown) that engages the floor bracket  32 . The combination of the floor bracket  32  and the cross pin passing through the locking aperture  36  supports the mast  22  along the floor slab  30 . 
     In the preferred embodiment of the invention illustrated, the floor slab  30  has an opening slightly larger than the outer diameter of the support mast  22 . However, since the support mast  22  has a smooth outer surface over its entire length, the support mast  22  can be easily raised and lowered through the concrete floor opening formed in the floor slab  30 . In previously available support structures for a concrete placing boom, the support mast included external projections that increased the difficulty in sliding the mast upward and downward through the concrete floor opening. Specifically, additional care was required to prevent damage to the concrete floor and the shaft itself. The support mast  22  illustrated in FIG. 1 is devoid of such projections, which allows the support mast to easily pass through such floor openings. 
     In the preferred embodiment of the invention, the support mast  22  has a length of approximately 12 meters. The length of the support mast  22  allows the concrete placing boom  10  to be located a sufficient height above the floor slab  30 , since concrete is often being placed at a level slightly above the floor slab  30 . Although not illustrated in the Figures, it is contemplated that the floor mast sections can be joined together such that the concrete placing boom  10  can be located higher above the floor slab  30 . In the preferred embodiment of the invention, the support mast  22  is formed from steel and has a weight of approximately 3,300 kilograms. 
     Referring now to FIG. 3, the top end  40  of the support mast  22  includes a top plate  42 . The top plate  42  is securely connected to the cylindrical outer wall  26  and closes the top end  40  of the support mast  22 . As illustrated in FIG. 3, the top plate  42  includes central guide opening  44  formed in the top plate  42 . The central guide opening  44  is centered along the longitudinal axis of the support mast  22  and has a diameter of approximately 15 cm. As will be described in greater detail below, the central guide opening  44  receives a guide pin  46  formed on the adapter  24 . 
     Referring now to FIG. 2, the pedestal  20  that is attached to the concrete placing boom  10  includes a plurality of depending ears  48  that are used to secure the pedestal  28  to the adapter  24 . Each of the ears  48  includes an opening  50  sized to receive an attachment pin  52 . As can be seen in FIG. 2, each of the ears  48  is attached to the pedestal base  54  by a support flange  56 . Each of the support flanges  56  are welded to the base  54 . 
     As the concrete placing boom, including the pedestal  20 , are lowered into contact with the boom attachment portion  23  of the adapter  24 , each of the ears  48  is received between an inner lug  58  and an outer lug  60 , as illustrated in FIG.  4 . As illustrated in FIGS. 4 and 5, the inner lug  58  and the outer lug  60  are spaced by a distance sufficient to receive the ear  48  formed on the pedestal  20 . Each of the inner lugs  58  and the outer lugs  60  include an opening  62  and  64  that are each sized to receive one of the pins  52 . As shown in FIG. 4, the pins  52  are able to secure the pedestal  20  to the adapter  24 . Each of the pins  52  receives a cotter pin  66  to ensure that the pin  52  does not inadvertently become disassociated with the adapter and pedestal. 
     Referring now to FIGS. 3 and 5, the adapter  24  is defined by a cylindrical outer wall  68  that extends between a top end  70  and a bottom end  72 . In the preferred embodiment of the invention, the adapter  24  has an overall height from the top end  70  to the bottom end  72  of approximately 184 cm and is formed from steel. The outer wall  68  includes a series of openings  74  that provide access for the concrete delivery lines for the placing boom  10 . Specifically, the delivery lines extend through the open interior of the pedestal and exit through the openings  74  and are connected to the placing boom  10 . 
     As illustrated in FIGS. 3 and 5, the boom attachment portion of the adapter  24  includes a top support plate  76  that is welded to the top end  70  of the outer wall  68 . The top support plate  76  is diamond shaped with each of its corners defined by one of the outer lugs  60 . The top support plate  76  is generally horizontal and supported by a series of support flanges  78  that are each attached at their upper ends to the top support plate  76  and are attached at their inner end to the outer wall  68  of the adapter  24 . The support flanges  78  aid in supporting the weight of the pedestal  20  and the concrete placing boom  10 , as best illustrated in FIG.  1 . 
     Referring back to FIG. 3, the adapter  24  includes a mast support plate  80  mounted within the open interior of the adapter  24  defined by the outer wall  68 . The mast support plate  80  defines the top end of a mast receiving receptacle  82 . The mast receiving receptacle  82  is defined by the outer wall  68  and the mast support plate  80 . 
     As can be seen in FIG. 3, the mast support plate  80  includes a central opening  84  sized to receive the guide pin  46 . The guide pin  46  includes a radial outer flange  86  that contacts the top surface of the mast support plate  80  to prevent the guide pin  46  from passing completely through the central opening  84 . The outer flange  86  is welded to the mast support plate  80  to hold the guide pin  46  in place. The guide pin  46  generally includes a cylindrical body portion  88  and a tapered tip portion  90 . The tapered tip portion  90  decreases in diameter from a widest point of 15.2 cm to a narrowest portion of 5 cm. 
     During the initial installation of the adapter  24  onto the support mast  22 , the top end  40  of the support mast is initially received within the mast receiving receptacle  82  of the adapter  24 . As the adapter  24  continues to move downward, the guide pin  46  comes into contact with the top plate  42  formed on the mast  22 . Specifically, the tapered tip portion  90  of the guide pin  46  enters into the central guide opening  44  formed in the top plate  42 . Since the guide pin  46  is tapered, the guide pin  46  aids in creating the proper alignment between the adapter  24  and the support mast  22 . 
     The adapter  24  continues to be lowered until the top plate  42  of the support mast  22  contacts the mast support plate  80  of the adapter  24 . Once these two elements are in contact with each other, the weight of the adapter  24  is completely supported by the mast  22 . 
     After the adapter  24  is in position, a cross pin  92  is inserted through a cross pin opening  94  in the outer wall  68  of the adapter  24 . The cross pin  92  further passes through an aligned cross pin opening  96  formed in the outer wall  26  of the mast  22 . As shown in FIG. 6, the cross pin  92  passes through a second cross pin opening  98  formed in the mast outer wall  26  and a second cross pin opening  100  formed in the adapter outer wall  68 . As illustrated, the first and second cross pin openings formed in the adapter  24  and the support mast  22  are positioned 180° from each other to permit the cross pin  92  to pass through the two elements. Each end of the cross pin  92  receives a cotter pin  102  to secure the cross pin  92  between the adapter  24  and the mast  22 . 
     Once the adapter  24  has been positioned on the support mast  26 , a pressure coupling  104  contained on the mast receiving portion  25  of the adapter  24  is used to secure the adapter  24  to the mast  26 , as shown in FIG.  4 . In the preferred embodiment of the invention, the pressure coupling  104  includes a plurality of pressure screws  106  that are each received within a threaded nut  108  in contact with the outer surface of the outer wall  68  of the adapter  24 . Each of the screws  106  includes an external thread that interacts with an internal thread formed in the nut  106 . Thus, as the screw  106  is rotated, the inner end  110  of the screw  106  moves into contact with the outer surface of the outer wall  26  of the support mast  22 . As can be understood in FIG. 7, the outer diameter of the support mast  22  is less than the inner diameter of the outer wall  68  of the adapter  24 . Thus, tightening each of the eight screws  106  spaced equally around the outer circumference of the adapter  24  locks the adapter  24  into contact with the support mast  22 . 
     As can be seen in FIGS. 4 and 7, each of the nuts  108  is entrapped between a top plate  110  and a bottom plate  112  that define a channel  114  around the outer circumference of the adapter  24 . As can be understood in FIG. 7, the channel  114 , and thus each of the nuts  108 , are aligned with a series of openings  116  formed in the adapter  24  to allow the screws  106  to press into contact with the mast  22 . 
     In the embodiment of the invention illustrated in FIG. 4, a strengthening plate  118  is connected across the open interior of the support mast  22 . The strengthening plate  118  is aligned with the points of contact between each of the screws  106  and the outer wall  26  of the mast to provide additional support for the tubular outer wall  26 . The strengthening plate  118  includes a central opening  120  to reduce the overall weight of the plate. 
     Although not illustrated in the Figures, a work platform can be supported beneath the adapter  24  to allow persons to stand underneath the concrete placing boom  10 . Specifically, a work platform is supported by support rods  122  that pass through each of the support flanges  78 . Since the work platform is associated with the adapter  24 , only a single work platform is needed at a work site. For example, when the adapter  24  is moved from one mast to another, the work platform can be moved along with the adapter. 
     Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.