Patent Application
20050163565
The present invention relates generally to chutes for concrete delivery trucks and, more particularly, to chutes for concrete delivery trucks that discharge uncured concrete onto a subgrade upon which a concrete slab will be formed.
One of the most common practices for the placement of concrete during the construction of slab-on-grade concrete surfaces and floors is to discharge concrete directly from concrete delivery trucks via a chute onto a subgrade upon which the slab will be formed. Discharging the concrete from modem trucks is typically at least partially automated when state-of-the-art trucks are used. In cases where the truck has a front discharge chute, the truck driver is often required to perform the task of controlling the concrete chute from the driver's seat. However, considerable manual labor is required to spread the concrete to a reasonably uniform depth for subsequent strike-off and/or screeding of the placed and spread concrete. Automated machines, such as the Laser Screed™ laser-guided screeding machine manufactured by Somero Enterprises of Houghton, Mich., USA, reduce the manual labor of screeding concrete substantially over large areas. However, in many instances where a screeding machine cannot be used or where the screeding machine is not readily suited for the particular application, the concrete often is spread out or struck-off in a somewhat uniform fashion by manual effort, which is often very labor intensive and costly.
The present invention provides a chute and laser-guided strike-off and/or screeding device or machine that is operable to strike-off and at least partially finish the uncured concrete placed at a site as it is discharged from the concrete truck delivery chute. In an effort to reduce the labor and cost associated with manual spreading out and striking off of the uncured placed concrete, the device of the present invention, which may be described as a “concrete-chute striking-off and/or screeding machine or device”, may be implemented. The device may be used to strike-off and more evenly finish the concrete substantially immediately as the uncured concrete is directly discharged from the ready-mix concrete truck delivery chute. The expected benefits of the concrete-chute striking off and/or screeding machine of the present invention include that little or no additional manual labor or equipment may be required in order to place, strike-off, rake, or otherwise spread out and screed the uncured concrete to a desired grade elevation at the job site. The present invention thus may be especially useful where current methods and machines are not practical or are unable to be used for a variety of reasons.
According to an aspect of the present invention, a concrete chute strike-off device includes a frame portion adapted to mount to a discharge end of a chute of a concrete delivery truck, a strike-off member adjustably mounted to the frame portion, a sensing device for sensing an elevation, position and/or orientation of the strike-off member, and a control operable to automatically adjust the strike-off member relative to the frame portion in response to a signal from the sensing device. The strike-off device is thus operable to strike-off uncured concrete as the uncured concrete is delivered to a subgrade surface by a chute of a concrete delivery truck. The control is operable to adjust the strike-off member relative to the frame portion while the strike-off member strikes off the uncured concrete at the subgrade surface.
The strike-off member may be pivotally mounted to the frame portion, and the sensing device may comprise a level sensing device. The strike-off member may be pivotable or tiltable about first and second generally orthogonal and generally horizontal pivot axes. The level sensing device may determine a degree of tilt of the strike-off member about the first and second pivot axes. The control may adjust the orientation or tilt of the strike-off member about the first and second pivot axes in response to a signal from the level sensing device.
The strike-off member may be vertically adjustable relative to the frame portion, and the sensing device may comprise a laser receiver for receiving or sensing a laser reference plane of a laser system. The control may vertically adjust the strike-off member relative to the frame portion in response to a signal from the laser receiver.
According to another aspect of the present invention, a method for striking off uncured concrete as it is discharged onto a targeted subgrade surface by a chute of a concrete delivery truck includes providing a concrete strike-off device having a frame portion and a strike-off member adjustably mounted to the frame portion. The frame portion is attached to an end of a chute of a concrete delivery truck. The concrete delivery truck discharges uncured concrete to the subgrade via the chute. The chute provides a channel or conduit for uncured concrete to flow from the concrete delivery truck to the targeted subgrade. The uncured concrete is struck-off as it is discharged to the targeted subgrade by the chute. The strike-off member is adjusted to a desired grade while striking off the uncured concrete.
Therefore, the present invention provides a strike-off device or machine for striking off uncured concrete as it is discharged from a chute of a concrete delivery truck. The strike-off device is operable to strike-off the uncured concrete at a desired grade to limit or reduce the manual labor that otherwise may be required to set or establish the desired grade of the concrete slab as the uncured concrete is discharged onto the targeted subgrade or surface. The strike-off device may be vertically adjusted in response to a laser leveling system to provide the desired grade of the concrete slab. The strike-off device may also or otherwise be tilted forward/rearward about a laterally extending axis and/or side-to-side about a longitudinally extending axis, in order to adjust the orientation or tilt of the strike-off member or device while the strike-off device is striking off the uncured concrete. The present invention thus provides an automatically adjustable strike-off device for striking off and spreading out uncured concrete as it is discharged onto the targeted area or surface by a discharge chute of a concrete delivery truck.
These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.
Referring now to the drawings and the illustrative embodiments depicted therein, a concrete chute screeding or strike-off device or apparatus or machine 10 is operable to strike-off and/or screed freshly placed and uncured concrete at an end of a discharge chute 12 (
The control means or system 18 may control the elevation of the V-shaped plow, such as in response to a laser control system or the like. For example, such a laser control system may utilize essentially similar laser-based machine control technology as that described by commonly assigned U.S. Pat. No. 4,655,633, which issued Apr. 7, 1987, and which is hereby incorporated herein by reference. Such machine control technology is included within laser-guided screeding machines currently manufactured by Somero Enterprises. Such screeding machines typically are implemented to control the elevation of a screed head that is supported by a telescopic boom assembly. The telescopic boom of such machines may be retracted toward the stationary base of the machine while the screed head may be engaged with uncured concrete that has been previously placed over a subgrade.
The concrete chute strike-off device of the present invention is constructed and operates as discussed below. The V-shaped plow 14 on the concrete chute strike-off device 10 is attached to the lower end of a generally vertical mast member 22 that can slide or move vertically inside a mast support tube 24. The support tube 24 is mounted to a frame 32 and extends generally vertically upwardly therefrom. An actuator 26, such as an electric linear actuator or a hydraulic cylinder (as shown in
In the illustrated embodiment, a laser receiver 28 is attached to the upper end of the mast member 22. The laser receiver 28 senses the position of a laser plane generated by an on-site laser transmitter (not shown) located at or near or adjacent to the area of operation of the device. The laser receiver generates an electrical output signal, which is directed to the input of a controller or control box 18 located on the screeding apparatus. The controller or control box 18 is operable to adjust the position or extension/retraction of the vertical mast 22 and thus the plow 14 relative to the support tube 24 and the frame 32 in response to the signal from the laser receiver. For example, the controller may operate a hydraulic valve or solenoid valve 27 (
During operation, the controller correctively controls or adjusts the elevation position of the vertical mast member, laser receiver, and V-shaped plow relative to the subgrade surface, such that the laser plane generated by the laser transmitter of the laser system remains substantially centered within the “on-grade” portion of the laser receiver's sensing element. Thus, the controller maintains the V-shaped plow at a substantially fixed or constant relative height or distance from the generated laser plane at the site. For example, if the plow, and hence the laser receiver, were to fall below or rise above the desired grade, the controller would receive either a corresponding “low” or “high” signal from the laser receiver. The controller would then output a signal to move or adjust the hydraulic cylinder or electric actuator to accordingly raise or lower the receiver. Therefore, the height or elevation of the V-shaped plow is substantially accurately maintained at the desired “on-grade” elevation position while it engages the uncured concrete during its operation. As used herein, the term “grade” is meant to describe the desired level or height of the concrete on the subgrade or support surface after the concrete has been placed and struck off.
Optionally, and in addition to the elevation control described above, the cutting edge of the V-shaped plow may be controlled so that it remains in a generally horizontal plane during its operation. This may be accomplished by means of pivotal mounting of the plow mast support tube 24 to the frame portion via a dual axis trunnion or central frame portion 30 that is pivotally mounted to an outermost trunnion frame portion 31 of frame 32, which may be mounted to or attached to or at the discharge end of the chute 12. The plow 14, support tube 24 and central frame portion 30 thus may be pivoted about a pair of generally orthogonal pivot axes 34a, 34b with respect to the outer frame portion 31. Two pivot axes 34a, 34b are thus provided, with each pivot axis being generally perpendicular with respect to the other and oriented in a generally horizontal plane. The first and outer most trunnion axis 34a may be referred to as a “fore aft trunnion axis”, while the second and innermost trunnion axis 34b may be referred to as a “side-tilt trunnion axis”. Two independent linear actuators or hydraulic cylinders 36, 38 may control the relative vertical position or rotation of the central assembly (comprising the central frame portion 30, vertical mast members 22, 24, laser receiver 28, and V-shaped plow 14) about both trunnion axes 34a, 34b, respectively, and relative to the outer frame portion 31 of frame 32.
In the illustrated embodiment, the controller or control box 18 receives an output signal from a level sensor 40 fixedly-mounted to the mast support tube 24. The level sensor in a particular embodiment of the present invention is of a dual-axis swinging pendulum type, but may comprise other types of level sensors, without affecting the scope of the present invention. Damping fluids or oils of various viscosities may be included within the level sensor to reduce or damp-out the effects of vibrations or jarring movements within the apparatus in an effort to improve the control response characteristics of the device. Other methods of level sensing technology or multiple sensors may optionally be used to measure the degree of levelness of the mast support tube, without affecting the scope of the present invention.
Low friction pivot bearings for the trunnion pivot axes and the fixed ends of the actuators may be housed within the trunnion frame. The trunnion frame subassembly 32 may in turn be fixed to a mounting bracket 42 adapted to be rigidly or otherwise securely attached at the discharge end 16 of the outermost end section of a series of concrete delivery truck chute sections 12a. Since the entire apparatus is attached at the discharge end 16 of the concrete chute 12, it will move up and down or change angular position relative to the ground based on any movement of the concrete truck 20 and chute 12. However, the response characteristics of the control system are preferably selected such that the hydraulic cylinders or actuators will strive to keep the bottom edge of the V-shaped plow at the desired correct elevation (such as in response to the laser receiver 28) for working the concrete. In addition, the V-shaped plow may be maintained in a generally horizontal plane (such as in response to the level sensors or controls 40) regardless of how the truck or chutes are moved over the support surface.
A general hydraulic schematic suitable for use with the chute strike-off device 10 is shown in
Apparatus Operation:
Referring now to
While discharging concrete down the chute or chute sections onto the subgrade, the discharging concrete will fall within the receiving area 14a or “V” of the bi-directional or V-shaped plow 14 and be struck-off to the desired grade by the lateral motion or side-to-side or arcuate motion of the bottom edge of the V-shaped plow. As the concrete is discharged at the plow, the chute (and strike-off device and plow) is pivoted or moved or swung in a side-to-side arcuate motion to place or distribute the concrete over the subgrade while the plow strikes-off the placed or distributed concrete. The elevation and tilt of the V-shaped plow is adjusted and substantially maintained in two axes throughout the lateral swing movement, thus substantially striking off and leveling the uncured concrete engaged by the V-shaped plow. Upon completion of a swing in one direction, the operator may reverse the truck, backing up slightly, and may proceed to repeat the swing and concrete screeding or leveling operation in the opposite direction. This process may be repeated until the entire load of uncured concrete has been discharged and placed at the targeted area. Since the control system is able to keep the bottom edge of the plow on-grade and within a generally horizontal plane, the uncured concrete will be accordingly struck off and substantially leveled. The generated laser plane at the site is directly correlated to the desired “on-grade” finished concrete elevation at the site.
Optionally, an alternate method of operation could allow the driver/operator of the concrete delivery truck and/or controls to continually but very slowly back-up the truck while continuously swinging the chute sections and screeding apparatus from side to side while discharging concrete onto the subgrade. Other methods of placing and striking off the concrete with the chutes and chute strike-off device may be implemented without affecting the scope of the present invention.
After the concrete truck and strike-off device or apparatus have discharged and struck off and substantially leveled the load of concrete, the concrete-chute strike-off apparatus may be set down on the ground, such as off to one side of the poured concrete. The strike-off device or unit may then be detached from the truck at the outermost end of the concrete chute. Alternately, the outer most concrete chute section or sections may remain attached to the strike-off device, without affecting the scope of the present invention. Any hydraulic lines and electrical control cables may then be disconnected, such as by use of quick-disconnect attachments or the like between the truck and the strike-off device. The concrete truck may then be driven away to secure another load of concrete as may be needed and/or a second truck may arrive on site with a full load as needed. The second truck may be equipped the same as the first and preferably may have the same quick disconnect hydraulic and electrical control cables as the first. The concrete chute strike-off device or apparatus may thus be attached to the chute of the second truck and moved into position, and the placing and striking-off process may be continued. Multiple trucks may be equipped in this way to continue strike-off and/or screeding operations indefinitely or at different sites as desired.
Optionally, when the concrete striking off and leveling operations are fully completed for the day, the concrete-chute screeding apparatus may be pressure washed, detached from the last truck, partially disassembled, and stored on-board the truck for transport away from the site. The entire apparatus is preferably light enough in weight such that when partially disassembled for transport, the components can be lifted, carried, and stored away by one or two workers until needed again.
Optionally, and additionally, and with reference to
Although shown and described as a generally V-shaped plow, the plow of the strike-off and/or screeding device may be replaced by a curved plow or a crescent-shaped plow or a circular or ring-shaped plow or any other shaped plow or strike-off beam or other suitable strike-off member or the like, without affecting the scope of the present invention. The plow or strike-off member thus may be formed to define the receiving portion or area for receiving the uncured concrete at the subgrade surface and generally in front of the plow or strike-off member such that movement of the plow or strike-off member over and along the concrete at the subgrade surface strikes off the placed uncured concrete and generally established the desired grade of the uncured concrete. Likewise, the vibrating member (if applicable) may comprise any suitable shape, such as a shape that generally corresponds to the shape of the plow or strike-off member, or any other shape as desired, and optionally may comprise two vibrating members oriented at an angle relative to one another.
Optionally, the strike-off member or plow and/or vibrating device (if applicable) may comprise other shapes as desired, depending on the particular application of the strike-off device or apparatus. For example, and with reference to
As shown in
The lower end of the support tube 124 is attached to an elongated mounting bar or member 135, which is oriented generally normally or orthogonal to the pivot axis 134a. The strike-off member 114 may comprise a single “non-V-shaped” member or a substantially straight member or beam or the like that is adjustably or movably mounted to the elongated mounting member 135. In the illustrated embodiment, the strike-off member 114 is supported at a forward end 114a by a generally vertical pivot pin 137 extending generally downwardly from a forward end 135a of mounting member 135, such that the strike-off member 114 may pivot or swing side to side about the generally vertical pivot pin 137. A rearward end 114b of the strike-off member 114 may be attached to or supported by a pivot limiting device or “slide-bar” 139 or the like. The slide bar 139 (which may comprise a generally rigid bar or member that extends generally laterally and generally normal or orthogonal to the longitudinal axis of the strike-off member) is slidably or adjustably or movably connected to or engaged with a rearward end 135b of the elongated mounting member 135, such as slidably received within a receiving portion 135c at rearward end 135b of mounting member 135.
The slide bar 139 allows the strike-off member or plow to swing horizontally to either side of the support or mounting member 135, and limits pivotal movement of the strike-off member at the outer ends of the desired pivotal range of motion of the strike-off member. For example, the slide bar 139 may include end plates 139a that contact the receiving portion 135c to limit further pivotal movement of the strike-off member in that direction. The strike-off member 114 thus may pivot in one direction as the strike-off apparatus 110 is moved in one direction over the placed concrete, and then may pivot in the other direction toward the other side when the strike-off apparatus is moved in the other direction over the placed concrete. Such a mounting arrangement and pivot limiting means of the strike-off member allows the strike-off member to “get behind” or follow the concrete being placed by the chute 112 when the strike-off apparatus is moving in a left or right generally lateral (or arcuate) direction. The generally straight strike-off member or plow is then able to strike-off the concrete in either the left or right directions. The range of pivotal movement of the strike-off member or plow may be set (and may be dictated by the length of the slide bar) to provide the desired angle of the plow relative to the direction of travel of the strike-off device.
A further advantage of the substantially straight strike-off member and mounting arrangement is that the control system for the strike-off apparatus 110 may be simplified because only one axis of rotation is needed due to the “single edged” strike-off member or plow. Optionally, the strike-off apparatus 110 may also or otherwise include a vibratable member or beam (not shown in
Optionally, the strike-off and/or screeding apparatus of the present invention may be at least partially supported at the concrete surface, and therefore further controllably stabilized relative to the desired grade. For example, the screeding apparatus may be at least partially supported by a trailing contact face of a plow or the face of a vibrating member that is at least partially supported by the uncured concrete surface, without affecting the scope of the present invention. For example, the strike-off and/or screeding device or apparatus may utilize aspects of the screeding devices described in U.S. patent applications, Ser. No. 10/266,305, filed Oct. 8, 2002 (Attorney Docket SOM01 P-318C); Ser. No. 10/728,620, filed Dec. 5, 2003 (Attorney Docket SOM01 P-318D); and Ser. No. 10/902,528, filed Jul. 29, 2004 (Attorney Docket SOM01 P-326), which are hereby incorporated herein by reference.
Therefore, the present invention provides a concrete strike-off and/or screeding device that is attached at the end of a delivery chute of a concrete delivery truck and that is operable to strike-off and/or level and/or screed the uncured concrete placed on the subgrade by the chute of the truck. The chute strike-off and/or screeding device of the present invention thus may strike-off and/or level the uncured concrete as it is placed at the targeted area, such that manual labor is not required to initially strike-off excess concrete to the desired grade. The device may include a vibrating member or screeding element to further process or work or finish the struck-off concrete at the subgrade.
Changes and modifications to the specifically described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law.
The present application claims benefit on U.S. provisional application, Ser. No. 60/539,775, filed Jan. 27, 2004, which is hereby incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60539775 | Jan 2004 | US |
