Scaffold frames are a series of horizontal and vertical scaffold frame members that connect together to create a raised working platform. The overall structure is supported by the vertical scaffold members contacting the support surface, such as the ground.
Scaffold frames can be constructed from tube and clamp frame members, or from system scaffold members (modular scaffold systems). In system scaffolds, the vertical scaffold members are coupled to horizontal scaffold members at a scaffold joint. A modular scaffold joint comprises a connector on the vertical scaffold member that is designed to couple or mate with a connector on a horizontal scaffold member, thereby joining together a horizontal and vertical scaffold member. Horizontal scaffold members will be referred to in general as “horizontals,” while vertical scaffold members will be referred to generally as “verticals” irrespective of the joint/connector type.
One type of modular scaffold joint uses an end connector positioned on the end of a horizontal member, where the end connector has a lip or hook section. The lip sections are designed to engage or rest on the corresponding vertical joint connector, such as an upstanding cup or an annular ring positioned on a vertical scaffold member. One such joint is disclosed in U.S. Pat. No. 4,445,307, which discloses a connector positioned on a horizontal scaffold member, where the connector has two vertically spaced hook sections.
These hook sections couple with two vertically spaced upstanding cup or ring members located on the vertical scaffold member. To lock the joint in place, the connector includes a wedge that is driven (generally by a hammer) into position below the upper ring member, thereby wedging the ring against the end connector hood section, latching the horizontal member to the vertical member. This type of connector is referred to as a Safway connector (see attached
Another cup type of latching connector is disclosed in U.S. Pat. Nos. 5,078,532 and 5,028,164 and in U.S. application Ser. No. 12/489,166 all hereby incorporated by reference. These patents also show an end connector positioned on a horizontal scaffold member, where the connector has two vertically spaced hooked sections that couple with two vertically spaced upstanding cup or ring members located on the vertical scaffold member. In this device, the hooked sections engage the top edge of the cup, and a pivoting member or latch, positioned on the horizontal end connector, is pivoted into position below the cup member. The latch member has a distal end extending beyond the housing, shaped to allow for placement of the distal end beneath a cup positioned on a vertical scaffold member. Hence, when latched, he cup is trapped between the hook engagement sections of the connector housing and the distal end of the latch member. The latch pivots on a pivot pin, and can be spring loaded to bias the latch into a locking or actuated position. This type of connector is referred to as an Excel connector (see attached
Another “cup” type of latching mechanism is disclosed in U.S. application Ser. No. 11/738,273, filed Apr. 20, 2007 (hereby incorporated by reference). This application teaches a horizontal scaffold member having an end connector with two hook or engagement areas, each designed to couple with a cup on a vertical member. The connector includes an upper and a lower latch, each the respective upper and lower coupled ring or cup members. The two latches are mechanically coupled allowing for single action operation to engage or disengage both latches simultaneously. In general, a system scaffold using a cup on the vertical member with a latch on the horizontal scaffold member (whether slidable or pivotable) will be referred to as a cup/latch scaffold system. This is also in the scope of an Excel connector.
Another cup-type of latching connector is disclosed in U.S. Pat. No. 3,992,118 (commonly referred to as the Cuplock system). As disclosed in this patent (see particularly
System scaffolds are used to allow for ease of erection of scaffold platforms. However, in some instances, it is not possible to erect a horizontal scaffold platform where the horizontal scaffold members are supported on four (or more) corners by downwardly extending ground supported vertical scaffold members. For instance, an elevated working surface may be needed that is connected to a self-standing scaffold structure, but where the platform is offset or cantilevered from the scaffold frame structure in order to extend the working platform over a structure (such as a tank). An offset working surface may be created by using a triangular shaped frame member connected to the scaffold frame structure (generally, two vertical members of the frame) to create an offset “knee out” structure that will support a cantilevered horizontal working surface. One such structure is shown in U.S. application Ser. No. 12/824,314 filed on Jun. 28, 2010, hereby incorporated by reference. However, when the offset working surface needs to extend more than about ten feet from the scaffold frame, a knee out support structure may not be feasible.
If the working environment includes overhead structures (often seen in bridge and offshore platforms), offset scaffold working surfaces with long platforms can be constructed by suspending the remote end (or intermediate portion) of the offset extended platform from the overhead structure. The suspended offset scaffold working surface makes long extended platforms feasible, but construction is arduous and dangerous. One method of erecting such an offset and suspended platform is as follows. A self standing scaffold structure is constructed adjacent to the overheard structure, with a working surface positioned at the desired height for the offset platform. From this working surface, a worker will couple an outwardly extending horizontal member to one of the vertical legs of the scaffold, to form an outwardly extending horizontal member supported only at one end by the couple to the vertical scaffold member. Placement of the extended horizontal, for instance, an eight foot long horizontal member, is awkward due to the weight of the horizontal member, and the fact that the horizontal member must be held in position perpendicular to the vertical member in order to couple to the vertical member, thus presenting large torque forces during installation. With a horizontal extending outwardly, a worker would tie off to the scaffold structure, and walk out on the extended horizontal (which is coupled to the scaffold frame at only one end). The worker would then connect a vertical to the free end of the horizontal, and then support the vertical from the overhead structure (such as by tying a rope or chain between the overhead structure and the vertical). The worker would return to the platform, and install a second outwardly extending horizontal, and similarly, attach a vertical to the remote end of this horizontal, and suspend this vertical from the overhead structure. Scaffold planks are then laid over the two suspended horizontals, creating a deck or working surface. A worker would then take a third horizontal, and connect the two suspended verticals to form a more rigid support frame for the working surface. Handrails can then be installed as desired between the verticals of the scaffold main frame and the suspended verticals.
As can be seen, this erection method requires a rigid joint between the horizontal and vertical scaffold member to allow a worker to safely walk out on an extended horizontal. For this reason, the preferred joint for this structure is the pinlock system, such as shown in U.S. Pat. No. 5,961,240, as a tight joint is needed to support a worker while working out on the extended horizontal. During the construction, the worker will generally be tied off to the overhead structure. However, even tied off, the procedure is dangerous and awkward. To join a horizontal to a vertical, the horizontal member must be held at a right angle to the vertical to allow the horizontal connector to couple to the vertical rosette or cup. This is difficult to accomplish due to the weight of the horizontal, and the length of the horizontal (7-10) feet. A safer apparatus and method of assembly is needed for building offset suspended scaffold decks.
Collectively, cups and rosettes, or other types of annular members on the vertical scaffold member used to couple to a horizontal end connector will be referred to collectively as annular members.
Shown in
As shown, three of the end connectors 90B, 90C, and 90D, are fixedly joined to the respective end of the horizontal pipe. However, one upper end connector, 90A, is pivotally coupled to the end of the upper horizontal pipe 10. As shown in
To accomplish horizontal pivoting, the horizontal connector body 90A (not shown in
This truss member 1 will be used to form one side of the extended offset platform. One method follows. A worker, working from the existing scaffold supported platform, such as from a horizontal scaffold deck, will tie a rope to the truss, and suspend the truss upright from the established scaffold structure, or from an overhead structure (such as a bridge member), where the suspended truss upper horizontal 10 is positioned adjacent to the vertical scaffold member to which it is to be coupled, with the couple 90A positioned adjacent to the corresponding joint on the vertical member (here a rosette). The truss member 1 will generally be supported or suspend “above” the corresponding couple rosette point on the vertical that will couple with joint 90A on the suspended truss. The worker will then adjust the rope until the pivoting end of couple 90A on the top horizontal scaffold member 10 is directly adjacent to and insertable into the proper rosette. Preferably, a second worker will then couple the horizontal connector 90A to the vertical connector (e.g. position the mouth of the horizontal connector body over the rosette by pivoting connector body 300 so that it is at substantially a right angle to the suspended upright horizontal member 10) and then lock the connector in place (drive in the pin through the connector and rosette opening). The first worker then lowers the rope, which results in the downward pivoting of the truss member about the coupled and locked joint 90A, in a vertical plane, until the lower connector body 90B is adjacent to the corresponding rosette on the vertical member. Preferably, the second worker then connects connector 90B with the proper rosette and locks the connector in place. One of the workers may slide the locking pin into the aligned opening in the ears of the upper bracket 300 as a safety measure (not required) to resist further rotation of the truss.
This procedure is repeated on an adjacent vertical of the existing scaffold structure, creating two truss members that are outwardly extending from the adjacent scaffold platform, each supported on one end only. At this point, the worker places scaffold planks between the two extended trusses, forming a working platform deck. In one embodiment of a scaffold plank, each end has downwardly extending U shaped brackets to couple the plank to the respective horizontal (where the horizontal is a circular pipe member). As each plank is about nine inches—a foot wide, multiple planks are slid out over the extended truss members. A worker will then move out on the new deck or platform, carrying a vertical scaffold member. The worker will then attach the vertical to the connectors 90C and 90D, and support the attached vertical to the overhead structure. Preferably, the overhead structure will have a component (such as a first beam) in a vertical plane that passes close to the vertical member to be suspended or the center of the resulting suspended platform (if the beam is substantially off “alignment” with the vertical to be supported, directly supporting the vertical to such a non-aligned overhead beam will not only provide an upward supporting force, but will also provide a horizontal force component, and a large horizontal force component is not preferred). For instance, a chain can be attached (such as looped around the overhead structure) to the overhead structure and tied to an eyebolt fixed or formed at the top of the vertical. A come-along can be used to shorten (or lengthen) the chain to position the truss member in a level position. A second vertical is coupled to the other truss member connectors 90C and 90D, and similarly supported by or suspended from the overhead structure (again, preferably, the overhead structure includes a second component, such as a beam, in a vertical that passes through or close to the center of the extended platform) and then modify the chain length to level the truss. thereby leveling the resulting platform. Horizontals can then be positioned between the two suspended verticals at the rosettes between corresponding 90D joins and 90C joins, to form a three sided suspended frame for the deck or offset working surface. The fourth side of the frame is formed by the ground supported prior existing scaffold frame structure. A single horizontal member may be used to join the two suspended verticals, such as at the level of the upper pipes 10, or the lower pipes 20, or two horizontal members used, one between the upper members, and one between the lower members of the opposing trusses. Additional horizontals may be joined between the suspended verticals, and between the suspended verticals and verticals of the existing scaffold structure, as needed, at a height above the installed deck for a safety rail. Alternatively, the outward vertical (that vertical that will attach to 90C and 90D on the truss members) can be attached to each individual truss member before the truss member is pivotally coupled or installed onto the existing support structure (such as an adjacent scaffold structure), or the outward vertical can be attached immediately after the truss member is pivotally connected to the existing support structure.
When the truss is initially installed and supported only on one end to a single vertical, the truss is supported on that vertical at two spaced apart locations—the upper joint 90A connection and the lower joint 90B connection to the vertical. This double connection creates a strong, stable joint. Additionally, because the truss itself forms a rigid structure, the single extended truss is more stable than a single extended horizontal. Although the truss member is heavier than a single horizontal, the pivoting joint allows the worker to install the truss vertically, reducing the torque forces that would be present in attempting to tie in the truss, or even a single horizontal at ninety degrees to a vertical (as the truss is supported as it is pivoted downward). A grab bar or handle may be included on the truss member to assist in operator manipulation of the truss during installation. Although the invention is described as a pivoting joint on a truss member, a pivoting connector may also be on a single horizontal scaffold member, as opposed to a truss member. While installation is eased with a pivoting horizontal joint, the single horizontal is not as rigid as a truss, and hence is not preferred, but is within the scope of the invention.
As described, the pivoting joint connector is located on the top horizontal of the truss member. As an alternative, the pivoting joint member may be positioned on the bottom horizontal (e.g. joint 90B), but this is not preferred. With a bottom pivoting joint, during installation, the vertically supported upright truss is positioned so the top of the upright truss is positioned adjacent the lower connector on the vertical, with the lower horizontal 20 immediately adjacent the vertical scaffold member. However, in this configuration, the vertically suspended truss 1 is generally suspended below the rosette or annular member that will couple with joint 90B, and hence the suspended truss, once the couple with 90B is established, must now be rotated or pivoted “upwardly” to allow the connector 90A on the top horizontal 10 to come into alignment with the upper connector on the vertical member (as opposed to “lowering” the vertically suspended truss from a pivoting connector on the top horizontal) This raising movement is considered more arduous, and hence, the pivoting bottom connector 90B is not preferred.
A second vertically pivoting truss is shown in
If two cup type connectors are desired to attached to spaced apart cups, a horizontally pivoting embodiment may be used (as later described), or the bottom connector at position 91B should be slidable vertically with respect to the horizontal member 20, so that the lower connecter 91B can be moved vertically upwardly, to clear the cup, then downwardly to engage the cup; alternatively, in some connector embodiments, instead of sliding vertically, the second end connector on lower horizontal may be rotatable about an axis aligned with the center of the horizontal member, thereby allowing the second end connector to be positioned adjacent the corresponding cup or rosette or other connector on the vertical, and rotated into proper coupling orientation (not shown). The horizontal position of such a rotatable or vertically slidable horizontal end connector preferably is lockable, such as with a pin, to prevent unwanted movement after engagement with the respective cup or rosette.
The truss member 1 is used to assemble an extended, vertically supported platform as the previous connector. Once one suspended offset platform is in place, this offset platform may now be used as the “fixed” scaffold, and another extended offset platform may now be attached, using a similar construction technique. For instance, if a 30×10 foot extended platform is needed off of an “fixed” scaffold frame, the first ten foot extended offset platform is erected as an outwardly extending platform to create a 10×10 offset platform. After this extension has been vertically supported, a second offset ten foot platform is built connected to the first offset platform at overhead supported end, thereby creating a 10×20 foot vertically supported offset platform, and so on until the desired length is reached (the suspended platform may also be 20×20, having three parallel trusses each 10 feet across, etc.). Breakdown or disassembly of the platform is performed in substantially the reverse order as assembly.
A third type of pivoting truss member is shown in 3. Shown here is a truss member 1 having pivoting connectors 90AH and 90BH. However, these connectors are designed to pivot in the horizontal plane (like a swinging fence gate), where “horizontal plane” is a plane ninety degrees to the orientation of a vertical member (e.g. parallel to the ground). Again, the preferred construction is to have the horizontal members 10 and 20 attached to a U shaped bracket 300, and the bracket 300 pivots with respect to the horizontal members 10 and 20. In this instance, the ears 301 of the bracket 300 are positioned on “top” and “bottom” of the horizontal members s 10 and 20 to provide for horizontal pivoting (whereas the vertically pivoting truss has the ears mounted on the “sides” of the horizontal members).
To build an offset vertically supported platform with this truss, the truss is installed in its natural orientation, horizontally. To avoid torque forces, the truss should be horizontal but not extending outwardly from the scaffold frame. Instead, the truss should be oriented so that it is adjacent the side of the scaffold platform. In this orientation, a worker can support the truss with almost no torque forces, if supported from the center of the truss (overhead support is not necessary). To attach, one worker supports the truss and connectors 90AH and 90BH are pivoted to face the respective annular members 80 for engagement and mounting. One worker holds the truss, while a second worker aligns the two truss connectors 90AH and 90BH with the respective connectors 80 on the vertical scaffold member, and joins the truss connectors to the vertical connectors and locks the connectors in place. The second horizontally pivoting truss is similarly installed on an adjacent vertical. The installed trusses are rotated horizontally (swung outwardly) until they extend outwardly and generally are perpendicular to the scaffold frame. As in the other methods, decking is laid, verticals are attached to the remote ends of the truss, and the verticals supported from an overhead structure. A similar horizontally pivoting truss in a cup/latch embodiment is shown in
Another horizontally pivoting truss embodiment is shown in
Another pivoting end connector truss embodiment is shown in
This end connector type (cup lock) may also be used in a vertically pivoting embodiment, but as with the vertically pivoting truss cup/latch system shown in
As described, the pivoting truss system can be used with most connector types, including traditional tube and clamp scaffolding. Scaffold pipes may be round or other shape. Each connector is configured to “connect” with an annular member on a vertical scaffold member—that is, when the connector engages the annular member, the join supports the truss (the truss may rotate, for instance, but the truss is nevertheless supported by the engagement or connection). The connection may automatically “lock” the vertical to the horizontal (such as in the Excel type spring loaded latch type connectors), or may require action on the part of the operator to lock the horizontal to the vertical (such as in the cup-lock type of connectors, the Safway type of connectors, or the pin-lock type of connectors).
Another embodiment of the truss member is shown in
It is understood that others have tried to use a system where the entire horizontal member, including the connector, pivots in the vertical connector (generally, a rosette). However, in such a system, the standard openings in the rosette cannot be used, as the openings in the standard rosette are designed to tightly couple the horizontal to the vertical. Hence, non-standard rosettes must be used, and hence, non-standard verticals. One of the benefits of the present system is that the standard vertical connector and standard horizontal connect can be used with no modifications, as the connector pivots with respect to the horizontal pipe. For pinlock type of connectors for vertical pivoting, the jaws of the opening on the truss member fixed connector may be widened to assist installation (see
The truss member connectors described as being fixedly attached to the upper or lower pipe may also be pivotally attached. As described above, the pivoting truss member is used to erect an overhead supported offset scaffold deck. The pivoting truss member is not limited to that application, as there may be applications where the stiffness and extra support of a truss member is needed in a non-overhead supported scaffold structure, and the pivoting truss allows for ease of installation in such applications.
This application is a continuation of U.S. application Ser. No. 14/265,074, filed on Apr. 29, 2014, which was a continuation in part of Application PCT/US2012/062557, filed on Oct. 30, 2012, which claimed the priority benefit of U.S. Provisional Application 61/599,118 filed on Feb. 15, 2012, and U.S. Provisional Application 61/628,607 filed on Nov. 2, 2011, all of which are incorporated by reference.
Number | Date | Country | |
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61599118 | Feb 2012 | US | |
61628607 | Nov 2011 | US |
Number | Date | Country | |
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Parent | 14265074 | Apr 2014 | US |
Child | 15053894 | US |
Number | Date | Country | |
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Parent | PCT/US12/62557 | Oct 2012 | US |
Child | 14265074 | US |