Fiber dispensing apparatus

Abstract

A fiber dispensing apparatus includes a hopper containing a plurality of fibers. A conveyor device having a plurality of flights thereon is provided at a bottom portion of the hopper. The conveyor device operates to move the fibers from the hopper into a fan-powered injector, which separates the fibers into an air stream and blows the separated fibers through a pipe system to a transit mixer.

Description

CROSS REFERENCES TO RELATED APPLICATIONS

[0001] This application claims the benefit of the U.S. Provisional Application Ser. No. 60/470,172, filed May 13, 2003 and U.S. Provisional Application Ser. No. 60/514,634, filed Oct. 27, 2003.

FIELD OF THE INVENTION

[0002] The present invention relates to fiber-reinforced concrete and more particularly, to a fiber dispensing apparatus for introducing fibers into concrete.

BACKGROUND OF THE INVENTION

[0003] In the construction industry, fibers are typically added to fresh concrete to improve the characteristics of the resulting hardened concrete structure. The fibers comprise steel, glass, or synthetic materials. Fiber-reinforced concretes have improved fracture toughness as well as a retarded degree of crack propagation.

[0004] These concrete-reinforcing fibers are typically packaged and sold in either water dissolvable paper bags or polyethylene bags. The fibers are added to the concrete mixer by either dumping the water dissolvable paper bags into the concrete mixer or by opening the polyethylene bags and shoveling or dumping the fibers directly into a concrete mixer during the concrete mixing operation. This labor-intensive task is often messy and can also result in a non-uniform dispersion of fibers when clumps of fibers become encased in the fresh concrete mixture and resist wetting due to their hydrophobic nature. Accordingly, it is desirable to have a means of dispersing concrete reinforcing fibers which is less labor intensive, less messy and more effective at uniformly distributing the fibers through out the mixture.

SUMMARY OF THE INVENTION

[0005] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is intended to neither identify key or critical elements of the invention nor delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.

[0006] In accordance with an aspect of the present invention, a fiber dispensing apparatus is provided. The fiber dispensing apparatus includes a hopper to hold a plurality of fibers; conveyor means positioned to move the plurality of fibers from the hopper; and an injector that receives the plurality of fibers from the conveyor means and separates the fibers into an air stream.

[0007] In accordance with another aspect of the present invention, a fiber dispensing apparatus includes a hopper to hold a plurality of fibers; conveyor means positioned to move the plurality of fibers from the hopper; at least one load cell to measure a weight of the hopper, the conveyor means, and the plurality of fibers; and an injector to separate the plurality of fibers into an air stream.

[0008] In accordance with yet another aspect of the present invention, a fiber dispensing apparatus includes: a first hopper to hold a plurality of fibers; conveyor means positioned to move the plurality of fibers from the first hopper; a second hopper mounted on load cells to measure an amount of fibers received from the first hopper; and an injector to receive the measured amount of fibers from the second hopper and separate the fibers into an air stream.

[0009] In accordance with yet another aspect of the present invention, a fiber dispensing apparatus includes: hopper means for containing a plurality of fibers; conveyor means for moving the plurality of fibers from the hopper means; and means for separating the plurality of fibers.

[0010] To the accomplishment of the foregoing and related ends, the invention then, comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the invention. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed and the present invention is intended to include all such aspects and their equivalents. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0011] FIG. 1 illustrates a perspective view of a low capacity fiber dispensing apparatus in accordance with an aspect of the present invention.

[0012] FIG. 2 illustrates a perspective view of a conveyor device that can be employed with the fiber dispensing apparatus in accordance with an aspect of the present invention.

[0013] FIG. 3 illustrates a perspective view of a medium capacity fiber dispensing apparatus in accordance with an aspect of the present invention.

[0014] FIG. 4 illustrates a perspective view of a high capacity fiber dispensing apparatus in accordance with an aspect of the present invention.

[0015] FIG. 5 illustrates a side view of the high capacity fiber dispensing apparatus in accordance with an aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention relates to a fiber dispensing apparatus, which stores and delivers fibrous material or fibers to transit mixers, such as ready-mixed concrete trucks, for instance, to form a fibrous mix of fiber reinforced concrete. The fiber dispensing apparatuses disclosed herein are operable to deliver a specific amount of fibers evenly into the concrete. The fibers employed with the fiber dispensing apparatuses are preferably synthetic fibers, e.g., polypropylene, polyester, or nylon. However, any suitable fiber formed from any suitable material can be utilized. Although the present invention will be described with reference to the embodiments shown in the drawings, it should be understood that various elements of the present invention could be incorporated into any suitable type of fiber dispensing equipment and is not limited to use merely in the illustrated embodiments and, may be incorporated in different types of embodiments. In addition, any suitable size, shape or type of elements or materials could be used.

[0017] Referring initially to FIG. 1, an example of a low capacity fiber dispensing apparatus 10 is illustrated in accordance with an aspect of the present invention. The fiber dispensing apparatus 10 includes a surge bin 12, or hopper, having an opening 14 at a top portion of the hopper 12. The hopper 12 is of a size suitable to hold up to about five cubic feet of fibers, and preferably about one cubic foot of fibers. However, the hopper 12 can be of any size to hold any suitable amount of fibers. Positioned near the hopper 12 is conveyor means 16. The conveyor means 16 is illustrated herein as a flat top conveyor that progresses in a direction indicated by arrow 18. However, it is to be appreciated that the conveyor means 16 can be of any suitable structure for moving the fibers from the hopper 12. For instance, the conveyor means 16 can be a turntable, a belt conveyor, a slat conveyor, a screw conveyor, a vibrating conveyor, a wheel conveyor, etc. A housing 20 and the hopper 12 substantially encloses the conveyor means 16. The housing 20 can comprise one or more components and includes an open portion 22 at a bottom of the housing. The open portion 22 is located below an end of the conveyor means 16. Positioned below the open portion 22 of the housing 20 is a chute 19. The chute 19 is coupled to an injector 24 via a T-shaped connector 26. A high-pressure fan 28 powers the injector 24. The T-shaped connector 26 can be coupled to a vertical pipe 30 via an elbow connector 32. A frame 34 is provided to support the fiber dispensing apparatus 10.

[0018] Turning now to FIG. 2, the fiber dispensing apparatus 10 with a portion of the housing 20 removed is illustrated in accordance with an aspect of the present invention. As shown, the conveyor means 16 can be a flat top conveyor having a plurality of flights 36 thereon. For example, the conveyor means 16 can be a slat conveyor having a plurality of slats 38, each slat 38 having at least one flight 36 projecting from a top portion of the slat 38. The flight 36 can be a rectangular-shaped projection wherein the length of the flight 36 is parallel with the length of the slat 38 from which the flight 36 projects. Further, flights 36 can be mounted on the conveyor means 16 in a zigzag pattern. Due to differences in capacity requirements and design preferences and the various types of fibers that can be employed with the fiber dispensing apparatus, it is recognized that many different flight patterns and configurations can be realized. Thus, it is to be appreciated that any suitable number of flights having any suitable structure and provided in any suitable configuration can be employed and is contemplated as falling within the scope of the present invention.

[0019] During operation of the fiber dispensing apparatus 10, an operator manually weighs a desired amount of fibers to be dispensed into the concrete. The fibers are then transferred to the hopper 12 via the opening 14 at the top portion of the hopper 12. The conveyor means 16 at the bottom of the hopper 12 moves the fibers in the direction indicated by arrow 18. The flights 36 on the conveyor means 16 are operable to push out a small amount of the fibers from the bottom of the hopper 12, over the end of the conveyor means 16, and through the open portion 22 of the conveyor housing 20. The zigzag pattern of the flights 36 maintains a continuous flow of fibers from the hopper 12.

[0020] The fibers then fall from the conveyor means 16, through the chute 19, and down to the injector 24, which is designed to create a vacuum that separates the fibers and sucks the fibers into the air stream. The injector 24 is further operable to blow the fibers upwards through the vertical pipe 30. The vertical pipe 30 is adjustable in height in order to comply with different heights of transit mixers. Although not shown, the outlet of the vertical pipe 30 can be fitted with different types of noses. For example, a straight nose can be utilized if the fibers can be blown directly into the transit mixer; otherwise, an s-shaped nose can be utilized if there are funnels or other obstacles at the outlet of the transit mixer. The fiber dispensing apparatus 10 can be portable or permanently installed at a cement mixing location.

[0021] FIG. 3 illustrates a medium capacity fiber dispensing apparatus 40 in accordance with an aspect of the present invention. The fiber dispensing apparatus 40 includes a hopper 42 having an open portion 44 into which a plurality of fibers can be dumped. The hopper 42 can hold up to about twenty-five cubic feet of fibers, preferably about twenty-two cubic feet of fibers. However, it is to be appreciated that the hopper can be of any suitable size to hold any suitable amount of fibers. A conveyor means 46 is provided at the bottom portion of the hopper 42. However, the conveyor means 46 can be located at any position suitable to move fibers from the hopper 42. The conveyor means 46 can be a flat top conveyor having a plurality of flights provided thereon. For example, the conveyor means 46 can be similar to the conveyor discussed and illustrated with respect to FIGS. 1 and 2, and thus, further discussion of the configuration of the conveyor means 46 will be omitted for the sake of brevity. However, it is to be appreciated that any suitable type of conveyor means 46 can be employed with the fiber dispensing apparatus 40.

[0022] The hopper 42 and a housing 48, with the exception of an opening 50 provided at a bottom portion of the housing 48, substantially enclose the conveyor means 46. The opening 50 is located below one end of the conveyor means 46. Provided below the opening 50 in the conveyor housing 48 is a chute 52, which leads into a T-shaped connector 54. The T-shaped connector 54 couples an injector 56 with a vertical pipe 58. An elbow connector 60 is provided between the T-shaped connector 54 and the vertical pipe 58. A fan 62 is also coupled to the injector 56 to provide power to the injector 56. A frame 64 is utilized to support the fiber dispensing apparatus 40. One or more load cells 66 are provided between the frame 64 and the conveyor housing 48. A control panel 68 is also secured to the frame 64 to provide operator control for the fiber dispensing apparatus 40. It is to be appreciated that the fiber dispensing apparatus 40 can be portable or permanently installed at a cement mixing location.

[0023] The hopper 42 can be manually supplied with a plurality of fibers. Alternatively, a vacuum conveyor (not shown) can be employed to transfer a plurality of fibers from a storage container (not shown) into the hopper 42. Further, unlike the low capacity fiber dispensing apparatus 10 discussed herein, the medium capacity fiber dispensing apparatus 40 can store more fibers than needed for one particular job.

[0024] During operation of the fiber dispensing apparatus 40, the conveyor means 46 moves fibers already present in the hopper 42 towards the opening 50. The flights on the conveyor means 46 operate to push out a small amount of fibers from the bottom of the hopper 42 into the chute 52. The fibers fall from the chute 52 into the T-shaped connector and are sucked into the air stream by the injector, thereby separating the fibers. The fibers are then transported by air through the vertical pipe 58 to a transit mixer. Because the hopper 42 and conveyor means 46 assembly is mounted on load cells 66, an amount of fibers dispensed from the hopper 42 can be precisely measured. For example, the amount of fibers dispensed from the hopper 42 can be measured by employed a loss of weight principal. When a predetermined loss of weight occurs in the hopper 42 and conveyor means 46, the conveyor means 46 stops. An operator can control the required amount of fibers that will be dispensed by the fiber dispensing apparatus 40 via the control panel.

[0025] Turning now to FIGS. 4 and 5, examples of a high capacity fiber dispensing apparatus 70 are depicted in accordance with an aspect of the present invention. The high capacity fiber dispensing apparatus 70 comprises a high capacity hopper 72, which can store up to about forty-five cubic feet of fibers, preferably about thirty-six cubic feet of fibers. However, it is to be appreciated that the hopper 72 can be of any suitable size to store any suitable amount of fibers. Similar to the low capacity fiber dispensing apparatus 10 and the medium capacity fiber dispensing apparatus 40, the high capacity fiber dispensing apparatus 70 includes a conveyor means 74 positioned to move the fibers from the hopper 72. As illustrated, the conveyor means 74 can be a flat top conveyor provided at a bottom portion of the hopper 72. The conveyor means 74 can include a plurality of flights (not shown) projecting from a top surface of the conveyor means 74. The conveyor means 74 can be similar in construction to the conveyor means illustrated and discussed with respect to FIGS. 1 and 2, and thus, further discussion of the configuration of the conveyor means 74 will be omitted for the sake of brevity. However, it is to be appreciated that any suitable type of conveyor means 74 can be employed with the fiber dispensing apparatus 70.

[0026] The hopper 72 and a housing 76 substantially enclose the conveyor means 74. The housing 76 can be constructed from one or more components and includes an open portion 78 located below one end of the conveyor means 74. Positioned below the open portion 78 is a chute 80, which leads to a weight hopper 82. The weight hopper 82 is mounted on one or more load cells 84, preferably four strain gauge load cells, and a slide gate 86 is coupled to a bottom portion of the weight hopper 82. A door 88 is provided below the slide gate 86. Located beneath the door 88 is a fiber blower assembly.

[0027] The fiber blower assembly includes a blower hopper 89 to receive the fibers from the weight hopper 82. Positioned to receive fibers from the blower hopper 89 is a second conveyor means, such as a rotating feed screw 90. The rotating feed screw 90 moves the fibers towards a separating wheel 92 provided at an end portion of the rotating feed screw 90. It is to be appreciated that any suitable means of conveying the fibers from the hopper 89 to the separating wheel 92 can be utilized. For instance, the fibers can be moved from the blower hopper 89 to the separating wheel via a belt conveyor, a vibratory plate or the like. The rotating feed screw 90 and the separating wheel 92 are adjustable in relation to speed (rpm) and can be of any suitable sizes to meet capacity requirements. The separating wheel 92 includes separating pins 94 coupled to at least one end plate 96. The separating pins 94 can be of any suitable length and quantity to meet capacity requirements.

[0028] The fiber dispensing apparatus 70 also includes an injector 98, which is coupled to a connector 100. A high-pressure fan 102 is also coupled to the injector 98 to provide power to the injector 98. The connector 100 can be coupled to a vertical pipe 104 via an elbow connector 106. A frame 108 is provided to support the fiber dispensing apparatus 70. A controller 109 is secured to the frame 108 and operates to control the fiber dispensing apparatus 70. A second housing 110 can be included to enclose the blower hopper 89, rotating feed screw 90, separating wheel 92, separating pins 94, end plate 96, injector 98, connector 100, and fan 102 to protect such components from the environment.

[0029] Similar to the medium capacity fiber dispensing apparatus 40, the hopper 72 for the high capacity fiber dispensing apparatus 70 can be manually supplied with a plurality of fibers. Alternatively, a vacuum conveyor (not shown) can be employed to transfer a plurality of fibers from a storage container (not shown) into the hopper 72. The hopper 72 can hold substantially more fibers than are required for one particular job.

[0030] During operation of the fiber dispensing apparatus 70, the conveyor means 74 moves the fibers from the hopper 72 to the chute 80, which transports the fibers down to the weight hopper 82. The speed of the conveyor means 74 can be controlled by a frequency inverter in order to adjust capacity. As discussed above, the flights projecting from the top of the conveyor means 74 can be mounted in a zigzag pattern to maintain a continuous flow of fibers into the weight hopper 82. It is to be appreciated that the flights can be of any suitable pattern and number in order to fulfill capacity requirements. The load cells 84 precisely measure an amount of fibers present in the weight hopper 82, which will be the amount eventually added to the concrete. Accordingly, when a desired amount of fibers is present in the weight hopper 82, the slide gate 86 will open and the fibers will be dumped into the blower hopper 89 of a fiber blower. An operator can control the desired amount of fibers that will be dispensed from the hopper 72 via the control panel 109.

[0031] Within the hopper 89 of the fiber blower, the rotating feed screw 90 transports the fibers towards the separating wheel 92. The separating pins 94 operate to separate the fibers from each other. After the fibers are separated, the fibers drop down into the injector 98. The high-pressure fan 102 powers the injector 98, which is designed to blow the fibers through the vertical pipe 104 to create a vacuum that sucks the fibers into the air stream and to further separate the fibers. At a bottom portion of the vertical pipe 104, the airflow is higher than at a central portion of the vertical pipe 104. Without the injector 98, the air profile will show the highest airflow in the central portion of the vertical pipe 104. Fibers will then drop down at the bottom of the vertical pipe 104 and the fibers will plug up the vertical pipe 104. It is therefore necessary to have a higher airflow at a bottom portion of the vertical pipe 104, which is accomplished with the injector 98 dividing the airflow.

[0032] The vertical pipe 104 is adjustable in height in order to comply with different heights of the transit mixers. The outlet of the vertical pipe 104 can be fitted with different types of noses. For instance, straight noses are employed if the fibers can be blown directly into the transit mixer; and S-shaped noses are employed if there are funnels or other obstacles at an outlet of the transit mixer. It is to be appreciated that the fiber dispensing apparatus 70 can be portable or permanently installed at a cement mixing location.

[0033] What has been described above includes exemplary implementations of the present invention. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art will recognize that many further combinations and permutations of the present invention are possible. Accordingly, the present invention is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.

Claims

1. A fiber dispensing apparatus comprising:

a hopper to hold a plurality of fibers;

conveyor means positioned to move the plurality of fibers from the hopper; and

an injector that receives fibers from the conveyor means and separates the fibers into an air stream.

2. The fiber dispensing apparatus of claim 1, wherein the hopper is mounted on one or more load cells.

3. The fiber dispensing apparatus of claim 1, wherein both the hopper and the conveyor means are mounted on one or more load cells.

4. The fiber dispensing apparatus of claim 1, wherein the conveyor means includes a plurality of flights projecting from a top portion of the conveyor means.

5. The fiber dispensing apparatus of claim 4, wherein the plurality of flights are configured in a zigzag pattern on the conveyor means.

6. The fiber dispensing apparatus of claim 4, wherein the plurality of flights are rectangular shaped projections.

7. The fiber dispensing apparatus of claim 1, wherein the conveyor means is a flat top slat conveyor.

8. The fiber dispensing apparatus of claim 1, wherein the hopper includes an opening at a top portion for manually loading a plurality of fibers.

9. The fiber dispensing apparatus of claim 1, wherein the hopper is of a size suitable to hold up to about five cubic feet of fibers.

10. The fiber dispensing apparatus of claim 1, wherein the hopper is of a size suitable to hold up to about twenty-five cubic feet of fibers.

11. The fiber dispensing apparatus of claim 1, wherein the hopper is of a size suitable to hold up to about forty-five cubic feet of fibers.

12. The fiber dispensing apparatus of claim 1, further comprising a housing to substantially enclose the conveyor means, the housing having an opening at a bottom portion of the housing located at one end of the conveyor means.

13. The fiber dispensing apparatus of claim 1, further comprising a chute located below one end of the conveyor means to transfer fibers from the conveyor means to the injector.

14. The fiber dispensing apparatus of claim 1, wherein the injector is powered by a high-pressure fan.

15. The fiber dispensing apparatus of claim 1, further comprising a pipe coupled to the injector to move the fibers into a transit mixer.

16. The fiber dispensing apparatus of claim 1, further comprising a control panel to control an amount of fibers dispensed from the hopper.

17. A fiber dispensing apparatus comprising:

a hopper to hold a plurality of fibers;

conveyor means positioned to move the plurality of fibers from the hopper;

at least one load cell to measure a weight of the hopper, the conveyor means, and the plurality of fibers; and

an injector to separate the plurality of fibers into an air stream.

18. The fiber dispensing apparatus of claim 17, wherein the conveyor means stops when the at least one load cell detects a predetermined loss in weight.

19. The fiber dispensing apparatus of claim 17, further comprising a control panel to control an amount of the plurality of fibers that are dispensed from the conveyor means.

20. The fiber dispensing apparatus of claim 17, further comprising a vertical pipe, wherein the injector blows the fibers through the vertical pipe directly into a transit mixer.

21. The fiber dispensing apparatus of claim 17, further comprising a chute provided between one end of the conveyor means and the injector to transfer the plurality of fibers from the conveyor means to the injector.

22. The fiber dispensing apparatus of claim 17, further comprising a plurality of flights projecting from a top portion of the conveyor means.

23. The fiber dispensing apparatus of claim 22, wherein the flights are configured in a zigzag pattern on the conveyor means.

24. A fiber dispensing apparatus comprising:

a first hopper to hold a plurality of fibers;

conveyor means positioned to move the plurality of fibers from the first hopper;

a second hopper mounted on load cells to measure an amount of fibers received from the first hopper; and

an injector to receive the measured amount of fibers from the second hopper and separate the fibers into an air stream.

25. The fiber dispensing apparatus of claim 24, further comprising a slide gate coupled to a bottom portion of the second hopper.

26. The fiber dispensing apparatus of claim 25, further comprising a third hopper positioned below the slide gate.

27. The fiber dispensing apparatus of claim 24, further comprising a rotating feed screw to feed the measured amount of fibers to the injector.

28. The fiber dispensing apparatus of claim 27, further comprising a separating wheel to separate the measured amount of fibers received from the rotating feed screw.

29. The fiber dispensing apparatus of claim 24, wherein the conveyor means includes a plurality of flights projecting from the conveyor means.

30. The fiber dispensing apparatus of claim 29, wherein the plurality of flights are configured in a zigzag pattern.

31. A fiber dispensing apparatus comprising:

hopper means for containing a plurality of fibers;

conveyor means for moving the plurality of fibers from the hopper means; and

means for separating the plurality of fibers.