US20070186504A1

US20070186504A1 - Device for tying and centering reinforcing bar

Info

Publication number: US20070186504A1
Application number: US11/353,713
Authority: US
Inventors: Peter Gavin
Original assignee: Polylok Inc
Current assignee: Polylok Inc
Priority date: 2006-02-14
Filing date: 2006-02-14
Publication date: 2007-08-16

Abstract

A device for tying and centering reinforcing bars within a cell of a concrete block. A housing adapted to be positioned adjacent the cell contains a tie, which extends from the housing. The tie includes a loop, a free end, at least one centering portion that engages the housing at one end and the loop at an opposite end, and teeth. The at least once centering portion is adapted to position the loop substantially within the center of the cell when the loop is closed around the reinforcing bars. When the free end is pulled, the loop is closed and substantially centered within the cell. Either the housing or the loop itself include a ratchet portion having teeth, which engage the teeth of the tie and hold the loop in a closed position after the free end of the tie is pulled.

Description

BACKGROUND OF THE INVENTION

(1) Field of the Invention
The present invention generally relates to a device for tying and centering reinforcing bar. In particular, the present invention is directed to a device for tying and centering reinforcing bar in a cell of a concrete block.
(2) Description of the Related Art
Concrete block construction is a common method for building walls in both residential and commercial structures. The typical block is a rectangular concrete block, which includes two openings or cells formed through the block. The concrete blocks are stacked on one another. A thin layer of mortar is positioned between the blocks to join them together.
After construction of the wall is completed, the cells of the blocks develop a matrix, which can be filled with concrete to increase the strength of the wall. Typically, steel reinforcing bar is positioned in the cells and extended vertically through the cells prior to filling the cells with concrete.
Generally, a foundation is laid prior to construction the concrete block wall. The foundation includes reinforcing bars that extend vertically upwardly from the foundation. The wall is then built on top of the foundation with the foundation reinforcing bars extending upwardly into cells of the concrete blocks. After stacking of the concrete blocks is completed, a second reinforcing bar is inserted from the top of the wall and through the various interconnecting cells. That bar is then tied to a foundation reinforcing bar before filling the cells with concrete to ensure that the inserted bar is vertical and maximize the final strength of the wall.
Because it is desirable to build the wall to its final height prior to inserting the reinforcing bar, a problem arises regarding how to tie the reinforcing bars together inside the wall cell. One common solution is for a worker to either punch holes in the wall or cut the concrete block adjacent where the reinforcing bars need to be tied together prior. Such a solution is undesirable because it requires subsequent repair of the wall. Another common solution is to tie a plurality of reinforcing bars together and to fabricate the wall in lifts. After tying each subsequent length of reinforcing bar to the lower length of reinforcing bar already installed, concreted block is lowered over the bar. This method is labor intensive and therefore slower than other methods.
U.S. Pat. No. 4,968,176 discloses parallel, side by side, sockets formed in metal strip or expanded metal for restraining the second reinforcing bar adjacent to foundation reinforcing bar while U.S. Pat. No. 6,141,937 discloses a spring clip for the same purpose.
U.S. Pat. No. 4,936,062 discloses a carrier that spans a cell and is held in place by mortar. The carrier has a downward facing groove extending around the periphery of the cell. A tie is threaded through the groove and held in place by restraining clips. When the second reinforcing bar is aligned adjacent to the foundation reinforcing bar, the ends of the tie are pulled taught. The tie disengages from the restraining clips and forms a tight loop holding the two reinforcing bars together. However, this system lacks a mechanism to insure the tied bars in centered in the cell. The U.S. Pat. Nos. 4,968,176; 6,141,937 and 4,936,062 are incorporated by reference in their entireties herein.
There remains, however, a need for an enhanced method for joining together adjacent reinforcing bars.

BRIEF SUMMARY OF THE INVENTION

One aspect of the present invention is a device for tying and centering reinforcing bars within a cell of a concrete block. The device includes a housing adapted to be positioned adjacent the cell and a tie including a loop and a free end that extends from the housing. The loop is adapted to be positioned substantially within the center of the cell when the loop is closed around the reinforcing bars. When the free end is pulled, the loop is closed and substantially centered within the cell.
Another aspect of the invention is a device for tying and centering reinforcing bars within a cell of a concrete block. The device includes a housing adapted to be positioned adjacent the cell and a tie including a loop and a free end that extends from the housing. The tie includes at least one centering portion that engages the housing at one end and the loop at an opposite end. The at least once centering portion is adapted to position the loop substantially within the center of the cell when the loop is closed around the reinforcing bars. When the free end is pulled, the loop is closed and substantially centered within the cell.
Still another aspect of the invention is a device for tying and centering reinforcing bars within a cell of a concrete block. The device includes a housing adapted to be positioned adjacent the cell and a tie including a loop and a free end that extends from the housing. The loop includes means for positioning the loop substantially within the center of the cell when the loop is closed around the reinforcing bars. When the free end is pulled, the loop is closed and substantially centered within the cell.
Yet another aspect of the present invention is a device for centering reinforcing bars within a cell of a concrete block. The device includes a housing adapted to be positioned adjacent the cell and at least one centering portion that engages the housing at one end and includes a ring at an opposite end. The at least once centering portion is adapted to extend to substantially a center of the cell so that the ring is adjacent substantially the center of the cell.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, the drawings show a form of the invention that is presently preferred. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:
FIG. 1 is a left-front isometric view of a device according to one embodiment of the present invention;
FIG. 2 is a right-back isometric view of a device according to one embodiment of the present invention;
FIG. 3 is an enlarged view of the device illustrated in FIG. 2;
FIG. 4 is an enlarged view of the device illustrated in FIG. 2, without reinforcing bars;
FIG. 5 is an exploded view of the device illustrated in FIG. 4; and
FIG. 6 is a left-front isometric view of a tie and centering portions according to one embodiment of the present invention.
FIG. 7 is an exploded views of the components of the system in accordance with a second embodiment of the invention.
FIG. 8 is a top isometric view of the cover of the system of the second embodiment.
FIG. 9 is a top isometric view of the base of the system of the second embodiment illustrating positioning of a cord by breakaway pins and pivot arms.
FIG. 10 is a top isometric view of the system of the second embodiment as assembled.
FIG. 11 is a top isometric view of the assembled system of FIG. 10 positioned in a concrete block.
FIGS. 12A-12D illustrate the assembly of FIG. 11 is top, bottom, front and side views, respectively.

DETAILED DESCRIPTION

Referring now to the drawings in which like reference numerals indicate like parts, and in particular, to FIGS. 1-5, one aspect of the present invention is a device 20 for tying and centering a first reinforcing bar 22 and a second reinforcing bar 24 within a cell 26 of a concrete block 28. In one embodiment, a housing 30, which contains a tie 32 and at least one centering portion 34, is positioned over cell 26. Tie 32 is used to tie reinforcing bars 22 and 24 to one another and at least one centering portion 34 ensures that the tied reinforcing bars are positioned substantially at a center 35 of cell 26. Housing 30 protects tie 32 and other components from being damaged by contacting wet mortar or reinforcing bars 22 and 24.
As best shown in FIG. 5, housing 30 includes a base portion 36, a skirt portion 38 that is adapted to fit within the base portion, and a cover portion 40 that is adapted to cover both the skirt portion and the base portion.
Base portion 36 generally has the same shape as cell 26, e.g., square or rectangular. In use, base portion 36 is placed on top of concrete block 28 with its perimeter tracing the perimeter of cell 26. Base portion 36 includes a raised sidewall 42 that surrounds a channel 44 that holds tie 32. Channel 44 may includes one or more wells 46 or indentations that correspond to the shape of tie 32. Channel 44 may also include anchor holes or detents 48 that engage centering portion 34. In one embodiment, first and second centering portions 34 engage first and second anchor holes 48 at first and second corners, 50 and 52, respectively, of housing 30. Tie 32 typically extends from housing 30 via a ratchet portion 54 formed in raised sidewall 42. Ratchet portion 54 may include teeth 56 that engage tie 32. Base portion 36 is generally fabricated from a material that includes some flexibility and significant strength characteristics, e.g., polypropylene or similar.
Skirt portion 38 is generally shaped to fit within base portion 36 and includes an interior wall 58 joined with a protective cover portion 60. Interior wall 58 typically has a height that corresponds to the height of tie 32 and sidewall 42. Interior wall 58 typically includes a plurality of slits 62 from which tie 32 may extend. Protective cover portion 60 may include holes 64 that correspond to anchor holes 48 of base portion 36 and serve to engage centering portions 34. Skirt portion 38 typically rests on channel 44. Tie 32 is substantially contained within channel 44 between sidewall 42, interior wall 58, and protective cover portion 60 when the tie is in a fully opened position. Skirt portion 38 is typically formed from a flexible, resilient material such as LLDPE-TPE or similar.
Cover portion 40 is shaped similarly to base portion 36 and includes a mortar contact flange 66 joined with a mortar cover portion 68. Mortar cut-outs 70 are defined in mortar contact flange 66 to help secure cover portion 40 in the mortar. A ratchet cover 72 and ratchet cover door 74, which correspond to ratchet portion 54, are also defined in mortar contact flange 66. Mortar cover portion 68 is sized to contain both base portion 36 and skirt portion 38. Mortar cover portion 68 includes a rounded inner edge 76 to facilitate insertion of reinforcing bars 22 and 24. Cover portion 40 is generally fabricated from a rigid, high-strength material such as a polycarbonate or similar.
Referring now to FIGS. 5 and 6, tie 32 includes a loop 80 and a free end 82 that extends from housing 30. One side of tie 32 generally includes teeth 84 or other raised portions that are adapted to engage teeth 56 of ratchet portion and hold loop 80 in a closed position after free end 82 is pulled. As shown in FIG. 6, alternatively, tie 32 includes teeth 84 and a ratchet portion 86 for holding loop 80 in a closed position after free end 82 is pulled. Loop 80 is adapted to be positioned substantially within center 35 of the cell 26 when the loop is closed around reinforcing bars 22 and 24. When free end 82 is pulled, loop 80 is closed and substantially centered within cell 26. Tie 32 typically includes at least one centering portion 34 that engages housing 30 at one end and loop 80 at an opposite end. Centering portion 34 typically engages loop 80 via a ring portion 88 and housing 30 via a peg portion 90, which fits in holes 48 and 64. As best shown in FIG. 3, in use when loop 80 is closed around reinforcing bars 22 and 24, first centering portion 34 engages first corner 50 of housing 30 and second centering portion 34 engages second corner 52 of the housing. Tie 32 is typically formed from a nylon material or similar.
FIGS. 7 through 11 illustrate a device for tying together adjacent reinforcing bars in accordance with a second embodiment of the invention. Certain features of this second embodiment are similar to features of the first embodiment described above. These common features are not described in detail with reference to the second embodiment. Referring to FIG. 7, the device 100 includes a flexible skirt 102 that is press fit into an aperture defined by an inner periphery 104 of a cover 106. A base 108 includes a plurality of breakaway pins 110 and an angled ramp 112 to support a cord locking wheel 114. A cord 116, such as a nylon cord, is disposed between the cover 106 and base 108 and positioned in a track 118 defined by breakaway pins 110 and a sidewall 120. Pivot arms 122 have a cord guiding loop 124 at a first end and a rotating post support 126 at an opposing second end. The rotating post support 126 is aligned by extending through a cover aperture 128 and a base aperture 130. The rotating post support 126 has a diameter less than the diameters of the cover aperture and the base aperture 130 to permit free rotation of the pivot arm 122 when a force is applied by the cord 116 through the cord guiding loop 124. Generally, the diameter of the rotating post support is about 0.06 inch less than the diameters of the cover aperture and the base aperture.
Referring to FIG. 8, the cover 106 is generally square or rectangular in shape with a length and width effective to span a cell of a concrete block and be supported on a surface of that concrete block. As shown in FIG. 12D, the length, L, runs along a long axis 132 of a concrete block 134 while the width, W, is transverse to that long axis. Extending from one side of the cover 106 generally transverse to the long axis 132 is a mortar shield top portion 136 to prevent motion of the cord 116 from being impacted by mortar. As shown in FIG. 12D, the height, H, of the cover 106 is less than the thickness of the mortar between successive rows of concrete blocks. An exemplary cover thickness is 0.25 inch.
Referring back to FIG. 8, cover aperture 128 has peripheral dimensions size to fit within a cell of a concrete block. Press fit into the cover aperture 128 is flexible skirt 102. The flexible skirt 102 is typically made from polypropylene or high density polyethylene and intended to prevent mortar or concrete from flowing into the device.
FIG. 9 illustrates base 108. The base has a length and width about equal to the length and width of the cover and a sidewall 120 slightly offset from the base perimeter such when the cover is placed over the base, the sidewall 120 is abutting the sidewall of the cover. Base aperture 130 has peripheral dimensions about equal to the peripheral dimensions of the cover aperture. Disposed between the sidewall 120 and base aperture 130 is a base interior flange 136. Projecting perpendicularly from the base interior flange 136 toward the cover are a plurality of breakaway pins 110 that are designed to shear when a force is applied to the cord 116. Typically the breakaway pins shear when an applied force exceeds about 25 foot pounds. The breakaway pins are typically formed during extrusion of the base component and have a nominal rectangular cross-section of 0.06 inch by 0.06 inch and nominal height of 0.25 inch. Sidewall 120 and breakaway pins 110 define a track 118 for the cord 116. The cord enters the base 108 through mortar shield bottom portion 140 and engages a cord locking wheel 142. The cord locking wheel in combination with an angled ramp 144 apply a pressure to the cord 116 such that a firm tug on the cord is required to activate the system. This avoids inadvertent premature movement of the cord.
The cord is looped around the track and passes through cord guiding loops 124of the pivot arms 122. A portion 148 proximate and internal end 150 of the cord 116 is bonded to the base 108 such as by melting or a sonic weld. Pulling on the cord 116 from external end 146 causes the loop to contract pivoting inward the pivot arms 124 forming a centered loop about a pair of reinforcing bars (not shown).
FIG. 10 illustrates the assembled system 100 and FIG. 11 illustrates the assembled system 100 positioned on a concrete block 134 in isometric view While FIGS. 12A through 12D illustrate respective top, bottom, front and side views of the assembled system positioned on a concrete block.
Although the invention has been described and illustrated with respect to exemplary embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without parting from the spirit and scope of the present invention. Accordingly, other embodiments are within the scope of the following claims.

Claims

1. A device for tying and centering reinforcing bars within a cell of a concrete block, said device comprising:

a housing adapted to be positioned adjacent the cell; and

a tie including a loop and a free end that extends from said housing, said loop adapted to be positioned substantially within a center of the cell when said loop is closed around the reinforcing bars, wherein when said free end is pulled, said loop is closed and substantially centered within the cell.

2. A device according to claim 1, wherein said house further comprises:

a base portion;

a skirt portion adapted to fit within said base portion; and

a cover portion adapted to cover both said skirt portion and said base portion.

3. A device according to claim 2, wherein said base portion includes a ratchet portion having teeth.

4. A device according to claim 2, wherein said base and skirt portions substantially contain said tie when said loop is in a fully opened position.

5. A device according to claim 3, wherein said tie includes teeth that are adapted to engage said teeth of said ratchet portion thereby holding said loop in a closed position after said free end is pulled.

6. A device according to claim 1, wherein said tie includes teeth and a ratchet portion for holding said loop in a closed position after said free end is pulled.

7. A device according to claim 1, wherein said tie includes at least one centering portion that engages said housing at one end and said loop at an opposite end.

8. A device according to claim 7, wherein said at least one centering portion engages said loop via a ring portion.

9. A device according to claim 8, wherein a first centering portion engages a first corner of said housing and a second centering portion engages a second corner of said housing.

10. A device for tying and centering reinforcing bars within a cell of a concrete block, said device comprising:

a housing adapted to be positioned adjacent the cell; and

a tie including a loop and a free end that extends from said housing, said tie including at least one centering portion that engages said housing at one end and said loop at an opposite end, said at least once centering portion adapted to position said loop substantially within a center of the cell when said loop is closed around the reinforcing bars, wherein when said free end is pulled, said loop is closed and substantially centered within the cell.

11. A device according to claim 10, wherein said tie includes teeth and a ratchet portion for holding said loop in a closed position after said free end is pulled.

12. A device according to claim 10, wherein said at least one centering portion engages said loop via a ring portion.

13. A device according to claim 10, wherein a first centering portion engages a first corner of said housing and a second centering portion engages a second corner of said housing.

14. A device for tying and centering reinforcing bars within a cell of a concrete block, said device comprising:

a housing adapted to be positioned adjacent the cell; and

a tie including a loop and a free end that extends from said housing, said loop including means for positioning said loop substantially within a center of the cell when said loop is closed around the reinforcing bars, wherein when said free end is pulled, said loop is closed and substantially centered within the cell.

15. A device according to claim 14, wherein said means for positioning include at least one centering portion that engages said housing at one end and said loop at an opposite end.

16. A device according to claim 15, wherein said at least one centering portion engages said loop via a ring portion.

17. A device according to claim 15, wherein a first centering portion engages a first corner of said housing and a second centering portion engages a second corner of said housing.

18. A device for centering reinforcing bars within a cell of a concrete block, said device comprising:

a housing adapted to be positioned adjacent the cell; and

at least one centering portion that engages said housing at one end and includes a ring at an opposite end, said at least once centering portion adapted to extend to substantially a center of the cell so that said ring is adjacent substantially the center of the cell.

19. A device according to claim 18, further comprising:

a tie including a loop and a free end that extends from said housing, said tie including teeth and a ratchet portion for holding said loop in a closed position after said free end is pulled, said loop adapted to be inserted through said rings of said at least one centering portion, wherein when said free end is pulled, said loop is closed around the reinforcing bars and substantially centered within the cell.

20. A device for tying and centering reinforcing bars within a cell of a concrete block, said device comprising:

a housing adapted to be positioned adjacent said cell, said housing including a track for receiving a cord,

said cord looped around said track with on end of said cord terminating within said housing and a second end extending outward from said housing; and

a plurality of pivot arms rotatably mounted to said housing at a post support end and receiving said loop through a cord guiding loop and an opposing end.

21. The device of claim 20 wherein said track is defined by a sidewall of said housing and a plurality of breakaway pins projecting perpendicularly from a flange of said housing.

22. The device of claim 21 further including a cord locking wheel engaging said cord at a point where said cord extend outward from said housing.

23. The device of claim 22 wherein said cord locking wheel is effective to require a force of at least 25 foot pounds to activate said device.

24. The device of claim 22 wherein an angled ramp is effective to cause said cord locking wheel to apply a pressure on said cord.

25. The device of claim 22 wherein said pivot arms are effective to keep said cord out of a central aperture circumscribed by said housing prior to rotation and center a loop formed by said cord within said central aperture subsequent to rotation.