Patent Application
20180370754
The invention relates generally to devices and methods used to prepare tendon used for post-tension reinforcement of concrete elements, and more particularly to such devices and methods which automate the cutting, coiling, and tying of such tendons into individual units prior to job site delivery.
Post-tensioning is the reinforcement methodology of choice for slab-on-ground, elevated slab applications and more. This engineered solution creates cast-in-place, pre-stressed concrete by tensioning the reinforcing concrete after the concrete has been placed. In unbonded post-tension construction, tendons are placed prior to concrete placement, and once the concrete reaches a specific initial compressive strength, the tendons are stressed to a specified force and anchored. Post-tensioning's external compressive force makes the concrete more resistant to the tensile stresses that would otherwise cause a concrete element (beam, slab or other member) to pull apart and crack.
Post-tensioning offers the builder a number of advantages, namely: (a) greater flexibility of design, because engineers can flexibly meet any geometric floor plan shape and use varying section dimensions in the floor plan; (b) reduced costs, because post-tension technology enables post-tensioned slabs to be constructed of a reduced volume of concrete, thereby reducing the builder's costs and providing a more economical solution; (c) adaptability to most soil conditions, because post-tensioning is an appropriate method of foundation reinforcement for stable soils and highly expansive soils alike; (d) reinforcement for a variety of applications, because post-tensioning is the reinforcement method of choice for both residential slab-on-ground and elevated floor slab applications, including single family homes, industrial floors, and high rise buildings; and (e) LEED points for green building initiatives, in that use of post-tensioning materials can add LEED (Leadership in Energy and Environmental Design) points toward a Green Building Certification in accordance with the U.S. Green Building Council's rating system.
An automated coiling system for post-tension tendon is provided, comprising a frame; a tendon feed device adapted to introduce a tendon into a coiler subassembly; a coiler subassembly adapted to grip and coil the tendon within a fixed volume having a predefined diameter; a plurality of wire tying devices adapted to securely tie a wire around the tendon bundle of widely varying diameter in a plurality of predetermined positions and cut the wire after tying; and a tendon ejector device adapted to urge a tied tendon bundle from the coiler assembly.
The above and other objects and features of the present invention will become apparent from the drawings, the description given herein, and the appended claims.
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements.
Before the subject invention is further described, it is to be understood that the invention is not limited to the particular embodiments of the invention described below, as variations of the particular embodiments may be made and still fall within the scope of the appended claims. It is also to be understood that the terminology employed is for the purpose of describing particular embodiments, and is not intended to be limiting. Instead, the scope of the present invention will be established by any appended claims.
In this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs.
As will be further described below with respect to the preferred embodiment, the present invention is an automated coiling system for preparing tendons used for post-tensioning reinforcement of concrete elements (slabs, beams or other members). The system employs devices and methods which automate the cutting, coiling, and tying of such tendons into individual units to then be bundled for delivery to a job site. In the preferred embodiment shown in
In
Post-tension tendons are constructed from tendons that are comprised of braided steel wires, coated with a friction reducing and corrosion preventative coating and enclosed within a continuous plastic sheath, and formed into large spools for later use. For any particular concrete element requiring post-tension reinforcement, the design engineers will specify the number, length, and features of the post-tension tendons for that job. Thus, individual tendons of widely varying lengths which are bundled by the present invention are cut to the proper length by a cutting device (not shown, but positioned before the diverter assembly 6) after a predetermined length of tendon is fed through the tendon feed system 2 and coiler assembly 3. Tendon material from the supply spool is pushed through the tendon feed system 2 by a roller drive system (not shown) that is set to feed a precise, but widely varying, length of tendon prior to being cut.
The tendon feed system 2 is provided with a diverter assembly 6 which diverts the tendon feed to either the left side or right side coiler assemblies 3. The diverter assembly 6 includes a tendon guide 9 mounted on a pivoting base 7 which partially rotates in a horizontal plane around pivot point 8. In this manner, the diverter assembly 6 is selectively moved to one of the two positions leading to either the left side or right side coiler assembly 3. For example, once a tendon has completely entered the left side coiler assembly 3, the diverter assembly 6 is moved to the other position so that a tendon can immediately be fed into the right side coiler assembly 3. Thus, the coiling of the right side tendon can commence while the left side tendon is being tied and dropped onto the platform for pickup by workers. In a production environment, tendons are successively and alternately fed into the left and right side coiling assemblies 3. For each side, a guide tube 9 is supported and connected to a plurality of opposing guide rollers 10 which are mounted to a roller base plate 11. The guide rollers 10 retain and guide the pushed tendon through a pivoting tube 12 until the tendon reaches a mechanical stop within the coiler assembly 3. At this time, the tendon is gripped by a clamp mounted to the coiler disk 15 so that it can be pulled into the coiler assembly 3 for coiling and tying.
As shown best in
To keep the varying length tendon bundle securely coiled for delivery to the job site, the fluctuating diameter tendon bundles are tied using a stiff wire at multiple locations around the bundle. The present invention automates this task by providing at least three wire tying subassemblies 4 positioned on the frame 1, and which interact with the different diameter tendon bundle when the coiler disk 15 is properly indexed relative to the tiers 4. A detailed view of the tier 4 is depicted in
Once the three initial wires have been applied to the tendon bundle, the coiler disk 15 is rotated approximately 180 degrees, so that the tendon bundle can be tied in up to three additional locations, for a total of up to six tied wires around the tendon bundle. Next to each of the tiers 4 is a tendon hold down device 21 for pushing on the tendon bundle during the tying step to urge the varying length tendon into a tight diameter at each tying location for maximum tying effectiveness. The tendon hold down device 21 includes a pushing head 22 at the end of an air cylinder and rod device 23. Thus, as each tier 4 moves toward to the tendon bundle, the tendon hold down device 21 moves toward the tendon bundle at the same time compressing the tendon bundle into a tight diameter and remains in place until the tying step is complete, after which the pushing head 22 is retracted.
With reference to
With reference to
All references cited in this specification are herein incorporated by reference as though each reference was specifically and individually indicated to be incorporated by reference. The citation of any reference is for its disclosure prior to the filing date and should not be construed as an admission that the present invention is not entitled to antedate such reference by virtue of prior invention.
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention set forth in the appended claims. The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
This application claims the benefit under 35 U.S.C. § 119 of provisional application, U.S. Ser. No. 62/484,749, filed on Apr. 12, 2017.
| Number | Date | Country | |
|---|---|---|---|
| 62484749 | Apr 2017 | US |
