Patent Application
20230332361
The present invention relates generally to concrete surface working machines for finishing of concrete that has been placed over a surface.
Screeding devices or machines are used to level and smooth uncured concrete to a desired grade. Known screeding machines typically include a screed head, which includes a vibrating member and a grade setting device, such as a plow and/or an auger device. The screed head is vertically adjustable, such as in response to a laser leveling system. Some machines use a rock tamping element that pushes down the aggregate in the placed concrete. The rock tamping element is mounted at the screed head and is raised and lowered with the screed head. Examples of screeding machines are described in U.S. Pat. Nos. 4,655,633; 4,930,935; 6,227,761; 7,044,681; 7,175,363 and 7,396,186, which are hereby incorporated herein by reference in their entireties.
As shown in
A concrete surface working machine for working or finishing or screeding a concrete surface includes a base portion and a screed head or concrete working head mounted at the base portion (such as at an end of an extendable and retractable boom that extends from the base portion). The concrete surface working machine is operable to selectively position the concrete working head at the concrete surface for a screeding or concrete working pass. The concrete working head includes a rock tamper adjustably attached at a frame of the head via a pair of support elements. The head includes a pair of actuators that, when actuated, adjust the support elements to adjust the rock tamper relative to the frame. The actuators are selectively controlled by an operator of the concrete surface working machine to adjust a height of the rock tamper relative to the frame and the vibrating element and the concrete surface being worked, such as before or after or during extension or retraction of the boom. For example, the actuator may be actuated to raise the rock tamper above the concrete surface while the concrete working head continues to work or process or finish or screed the concrete surface.
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 surface working machine 10 includes a base unit 12 (which may comprise a wheeled unit or may comprise any other form of base unit or structure) with a boom extending therefrom and supporting a screed head or assembly 14 at an outer end thereof (
Referring now to
As shown in
The rock tamper 16 is urged downward to push down the aggregate, so the aggregate does not pop or protrude through the surface during the concrete screeding or working process. If aggregate does protrude through the concrete surface, the small amount of cream covering the aggregate comes off and opens a small hole in the floor. The mesh cylinder 16a of the rock tamper 16 is rotatably mounted to the mounting tubes 18 at the lower ends of the inner shaft 16b so that, during operation, the mounting tubes urge the rock tamper downward and the mesh cylinder rolls along the concrete surface as the screed head is moved over and along the concrete surface during a screeding pass.
In the illustrated embodiment, the actuator 22 is disposed at each mounting tube 18 and is operable to move the upper shaft 18c relative to outer tube 18a, which compresses or relaxes the spring 18d and moves the lower shaft 18b relative to the outer tube to adjust the height of the rock tamper 16 relative to the frame of the screed head 14. As best shown in
The actuators thus can lift the roller of the rock tamper out of the concrete if necessary for some passes. For example, if the operator utilizes head rotate or machine rotate to move around a column, the metal roll or tamper would tear the concrete surface, but the actuators allow for the operator to raise the rock tamper out of the concrete during such operations. The actuators and mounting structure also allow the operator to set the depth of the roller or tamper at or above or below grade, such as by extending or retracting the actuator to raise or lower the tamper via control of the actuators at the operator seat. Also, the operator may increase the depth and/or pressure of the tamper at the concrete surface via controlling the actuator, such as for when the concrete slump decreases (i.e., the concrete gets harder) by retracting the actuator which compresses the spring and urges the lower shaft and the tamper downward.
The actuators may comprise hydraulic cylinder actuators or electrical linear actuators or other suitable actuators. For example, the actuators may comprise electric actuators that operate via a 12 volt power supply, and may provide position feedback to the system and/or operator. An example of a suitable actuator may be a linear actuator commercially available from Warner Electric of South Beloit, IL. The actuator may provide position feedback, and may have a built in brake, and is strong enough to raise and lower the tamper and to provide the desired height of the tamper relative to the auger. The actuator may operate to extend and/or retract at, for example, about 2 inches/second (under no load) or faster to provide the desired responsiveness when the operator actuates the actuator to raise or lower the tamper.
The actuators are disposed at respective ends of the roller or rock tamper and actuate to a position set by the operator, such as based on the slump of the concrete being worked. For example, if the concrete has a higher slump (less set up or more freshly placed), the operator may actuate the actuators to raise the roller and/or decrease the force applied by the spring. Similarly, if the concrete has a lower slump (more set up or partially cured), the operator may actuate the actuators to lower the roller and/or increase the force applied by the spring. Optionally, the actuators may operate to provide a soft landing of the roller/tamper at the concrete surface, such as at the start of a tamping pass (such as by utilizing aspects of the systems described in U.S. Pat. Nos. 8,038,365; 7,677,834; 7,396,186; 7,175,363 and/or 7,044,681, which are hereby incorporated herein by reference in their entireties).
Optionally, the actuators may comprise manual lift mechanism or manually actuated actuators with a locking mechanism, whereby an operator can manually raise the rock tamper, and the locking mechanism is engaged (such as via a latch latching the rock tamper in place when raised to a threshold level) to retain the rock tamper at the raised position. When it is desired to lower the rock tamper back down, the latch mechanism may be disengaged by the operator, and the rock tamper may be lowered to the concrete surface (such as in a controlled or dampened manner so that the rock tamper slowly lowers into engagement with the concrete surface).
As discussed above, the rock tamper 16 includes the metal mesh cylinder 16a, which is attached at the rod or shaft 16b, which in turn is mounted at each end to the bearing blocks 20. The bearing blocks 20 are attached at the lower end of the lower tube 18b of the mounting tube 18. Optionally, and such as shown in
Optionally, and such as shown in
In the illustrated embodiment, and as best seen with reference to
Thus, the fastened or bolted end plates and the segment end plates each include corresponding interlocking tabs/holes to ensure the entire assembly rotates as one unit. As shown in
The roller shaft may have an end plate attached at one end, whereby a first segment is slid onto the roller shaft and connected to the roller shaft end plate, and then additional segments are slid onto the roller shaft and connected to one another. After the last segment is at the roller shaft, the shims and other end plate are installed at that end of the roller shaft to complete the rock tamper assembly. If one or more of the segments is damaged, the damaged segment(s) can be replaced by removing one of the end plates and removing the segment and replacing just the damaged segment with a new segment. Optionally, the mesh segments may be provided with different mesh size or screen size (i.e., different sized holes or gaps) and may be changed to accommodate different sized aggregate or to function to push down the aggregate in different amounts (e.g., smaller screen size will push down more of the smaller aggregate and allow less aggregate to pass through the mesh into the cylinder). For example, the mesh may comprise a ½ inch mesh size, which has a rough diamond-shaped opening of about ⅜ inch by ¾ inch, but other suitable sizes may include, for example, ¼ inch, ¾ inch or 1¼ inch.
The rock tamper thus functions to push the aggregate lower into the slab of concrete than the normal screed head would. For lower slump (stiffer) concrete mixes, the rock tamper may run at a lower elevation (relative to the bottom of the auger) than it would for a higher slump (wetter) mix. By running the rock tamper ‘lower’ it will stiffen the spring so that when the roller engages the concrete, the concrete will push the roll upwards thereby compressing the spring and allowing more down pressure onto the surface of the concrete. For wet mixes, the spring may not compress, so the elevation of the rock tamp may be set higher, perhaps only, for example, one-quarter inch below the auger and just enough to make sure the rock gets pushed below the surface (such adjustment may be achieved via actuation of the actuator or adding or removing one or more shims at the bearing block). For either mix, the result should be the same—the rock should be some amount below the surface of the concrete, such as between, for example one-eighth of an inch to one-quarter of an inch or thereabouts.
The controller of the screeding machine individually controls the elevation cylinders of the screed head responsive to signals generated by the laser receivers, which sense a laser reference plane generated at the work site. Optionally, the screed head may be responsive to other sensors, such as ultrasonic sensors or laser sensors or the like that sense and maintain a distance or height of the head at and over the concrete surface, such as by utilizing aspects of the machines described in U.S. Pat. No. 6,227,761, which is hereby incorporated herein by reference in its entirety.
The screeding machine and the screed head or assembly may be similar in construction and/or operation as the screeding and/or finishing and/or spraying machines and heads described in U.S. Pat. Nos. 4,655,633; 4,930,935; 7,044,681; 7,175,363; 7,396,186; 9,835,610; 10,156,048 and/or 10,895,045, and/or U.S. Publication Nos. US-2022-0316154; US-2010-0196096 and/or US-2007-0116520, which are all hereby incorporated herein by reference in their entireties, such that a detailed discussion of the overall construction and operation of the machines and heads need not be repeated herein. However, aspects of this screeding and tamping machine are suitable for use on other types of machines. For example, the screed head and tamper may be suitable for use on a smaller machine, such as a machine of the types described in U.S. Pat. Nos. 6,976,805; 7,121,762 and/or 7,850,396, which are hereby incorporated herein by reference in their entireties. Optionally, the screed head may be used on other types of machines, such as a machine with the head mounted at an articulatable boom, such as of the types described in U.S. Pat. No. 10,190,268, which is hereby incorporated herein by reference in its entirety.
Therefore, the concrete surface working machine provides a rock tamper on a concrete screeding head and allows for selective adjustment of the height (and/or down pressure) of the rock tamper relative to the frame of the screed head (and thus relative to the plow and/or vibrating member of the screed head) via extension and retraction of the actuators. Thus, the height of the rock tamper and/or the spring force applied by the spring may be selectively set via the shims and/or selectively controlled by an operator to allow for increasing depth of the tamper into the concrete surface when used at firmer or more set concrete and raising the rock tamper off the concrete surface during particular screed head maneuvers, such as when the screed head is rotated or the machine rotates to move the screed head around a column.
Although shown and described as being disposed at a screed head having a vibrating member, the rock tamper and actuators and mounting structures may be disposed at other concrete surface working or finishing machines or devices, such as at a finishing machine with an adjustable float, such as a spraying and/or brooming and/or floating and/or finishing machine that utilizes aspects of the machines described in U.S. Publication No. US-2022-0316154, which is hereby incorporated herein by reference in its entirety. For example, the rock tamper may be installed on a broom and cure device to tamp the concrete surface ahead of a bull float of the concrete finishing machine. Also, although shown and described as being located at the screed head at a rearward or following position that would be behind and follow the plow and vibrating element during a screeding pass, the rock tamper may be positioned at the forward or leading end or side of the screed head to engage the concrete surface ahead of the surface working element (e.g., plow and vibrating element) as the screed head is moved over the concrete surface in a screeding direction. Optionally, with the rock tamper disposed at the trailing or following side of the screed head, the rock tamper may engage the concrete surface during extension of the boom, and the plow and vibrating element may engage the concrete surface during retraction of the boom. Optionally, with the rock tamper disposed at the leading side of the screed head, the rock tamper and the plow and vibrating element may engage the concrete surface during retraction of the boom.
Also, although shown and described as being adjustably disposed at the screed head, the rock tamper may be fixedly disposed at the screed head (or other concrete surface working or finishing machine), with the screeding element and grade setting member (or other working or finishing element or device) adjustable relative to the screed head and rock tamper. The vibrating element or other concrete finishing element may be adjusted relative to the rock tamper during the screeding or finishing pass along the concrete surface.
Changes and modifications to the specifically described embodiments can 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 the filing benefits of U.S. provisional application Ser. No. 63/362,901, filed Apr. 13, 2022, which is hereby incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63362901 | Apr 2022 | US |
