Static molds – Uniting preform with molding material – Preform supported by hole or recess in mold wall or surface
Reexamination Certificate
2000-07-06
2002-05-28
Davis, Robert (Department: 1722)
Static molds
Uniting preform with molding material
Preform supported by hole or recess in mold wall or surface
C249S002000, C425S063000, C425S110000, C404S006000, C404S100000, C404S105000
Reexamination Certificate
active
06394410
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the concrete construction and paving fields, and more specifically to a device for use with a mobile slip form concrete barrier construction machine. The present invention secures to such a machine and serves to guide preassembled steel reinforcement grids or screens into place as the barrier is formed, placing the reinforcement accurately within the concrete barrier as it is formed.
2. Description of the Related Art
Hundreds, if not thousands, of miles of concrete traffic barrier or retaining walls (i. e., “Jersey walls”) are placed or constructed annually during road and highway construction, building and parking lot construction, pavement resurfacing, etc. During temporary repaving or construction projects, most such barriers are prefabricated in predetermined lengths and temporarily placed in location as desired, using a crane or other suitable means. However, in many cases such barriers are intended for permanent placement, e. g., as dividers between opposed lanes on highways, traffic separators in areas where no shoulders exist along the roadway, as in crowded urban areas, etc.
Where such barriers are intended to be permanently installed, it is oftentimes more economical to construct the barriers in place, rather than prefabricating them in sections, transporting them to the site, and placing them as desired. As a result, machines have been developed which essentially extrude such concrete barriers as a continuous line, for use where a relatively long length of permanent barrier is desired.
The use of steel bars or other steel reinforcement in concrete structures is well known, and is known to increase the strength of concrete structures considerably. Accordingly, virtually all concrete traffic barriers or retaining walls make use of such steel reinforcement within the concrete structure. Such concrete barriers use at least a few reinforcement bars placed linearly therein, with additional steel reinforcement in the manner of one or more mats, grids, or screens being even more desirable.
While the use of reinforcing steel screens is desirable for the superior strength provided to the finished barrier, in the past their use has resulted in a relatively costly finished product. Either the contractor must buy (or make) prewelded reinforcement mats, or pour an additional footer and imbed the steel reinforcement structure in the footer and then form the concrete barrier around the reinforcement steel. Each of the above methods adds considerably to the cost of the completed job. In the case of welded steel mats, the welding reduces the strength of the steel at each welded joint, thus requiring the contractor to purchase higher strength (and more expensive) steel in order to meet the specified strength requirements of the contract. Hand tied mats are superior in this respect, but in the past have been difficult to incorporate in a concrete barrier structure without resorting to the additional step of pouring a separate concrete footer and imbedding the steel reinforcement in the footer, before pouring the barrier itself.
Accordingly, a need arises for a device for guiding placement of steel reinforcing mesh into a mobile continuous barrier forming machine, during the forming process. The present insertion guide is installed on the forming machine and positioned between the slip form mold walls. The present invention enables two preassembled reinforcing mats to be tied together at their upper edges, with the central separator of the guide serving to separate the two mats and spread them apart at their upper edges, positioning them accurately within the concrete as it is poured continually into the slip form.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 2,175,240 issued on Oct. 10, 1939 to Oscar F. Arthur, titled “Apparatus For Placing Reinforcement In Concrete” describes a generally horizontally oriented machine for forcing a single ply of reinforcing mesh downwardly into a fresh concrete surface, as in a concrete roadway, floor slab, etc. The Arthur machine cannot operate in a generally vertical plane, as it is not configured to operate with a slip form barrier mold. Moreover, the Arthur machine can only handle one ply of mesh at a time, rather than the two plies which the present invention is capable of handling.
U.S. Pat. No. 2,596,206 issued on May 13, 1952 to Fred D. Carnes, titled “Dowel Bar Installing Device,” describes a machine for placing dowel and tie bars into a horizontal poured concrete structure (paving, slab, footing, etc.). The device comprises a series of hooked fingers each supporting a dowel rod or the like, with the rods sliding from the hooks when they contact the fresh concrete. Each hook has an upper part which engages the rods to force them downwardly into the concrete, with the fingers clearing the rods when the fingers are lifted from the concrete. The Carnes machine cannot insert two plies of steel reinforcing mesh or screen into opposite sides of a concrete structure, nor can it install such reinforcing steel in a generally vertical structure or into a structure as it is being formed, as provided by the present guide.
U.S. Pat. No. 3,443,495 issued on May 13, 1969 to Carl J. Heltzel, titled “Concrete Reinforcing Steel Handling And Placing Device,” describes a machine for picking up reinforcement bars and the like and carrying them over freshly poured concrete, and placing them atop the concrete. The Heltzel machine does not actually place or locate the reinforcement bars within the concrete; this must be done by a separate machine. The Heltzel machine cannot be used with generally vertical concrete structures, as it merely places the reinforcement material atop a freshly poured horizontal slab. Also, the Heltzel machine cannot provide more than a single ply of reinforcement steel for the concrete, as the ply of steel placed is defined by the upper layer of fresh concrete upon which the steel is placed by the Heltzel device.
U.S. Pat. No. 3,678,816 issued on Jul. 25, 1972 to Michael I. Hudis, titled “Apparatus For Installing Reinforcing In Plastic Concrete,” describes a machine for depressing reinforcing rods or bars into freshly poured concrete, comprising a wheel having a series of paddles thereon for pushing the steel reinforcement into the concrete. The Hudis device thus performs essentially the same function as the devices of the Arthur '240 and Carnes '206 U.S. Patents discussed further above, and cannot guide or feed multiple plies of preassembled steel reinforcing mesh or screen into a generally vertical concrete structure as it is being continually and linearly formed, as provided by the present insertion guide invention.
U.S. Pat. No. 4,084,928 issued on Apr. 18, 1978 to Adolph R. Petersik, titled “Slip Form Having Reinforcement Accommodating Means,” describes a slip form mold having a hinged door or panel on the forward end thereof. The door includes slots and passages therein, for allowing continuous lengths of reinforcing rod or bar to pass through the closed door and into the mold, where it is encapsulated within the concrete. The slots of the door of the Petersik device extend laterally, with the ends being closed off when the door is closed. Thus, the Petersik device does not provide clearance thereinto for multiple plies of continuous preformed screens or meshes having a length and substantial width, as provided by the present insertion guide. Moreover, the Petersik device cannot be lifted for obstruction clearance (curbs, etc.) while in operation, as can the present reinforcement insertion guide.
U.S. Pat. No. 4,168,135 issued on Sep. 18, 1979 to Henry S. Johansson et al., titled “Casting Machine With Reinforcement Inserting Device,” describes a device for inserting transverse tie bars into freshly poured concrete, in a slip form mold for forming concrete barriers. The device is external to the mold, rathe
Davis Robert
Heckenberg Donald
Litman Richard C.
LandOfFree
Adjustable reinforcement insertion guide for a slip form... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adjustable reinforcement insertion guide for a slip form..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adjustable reinforcement insertion guide for a slip form... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2889122