FORMS AND SCREED FOR PAVING MATERIALS
An apparatus for installation of paving materials has a screed that is configured to extend across a gap between first and second forms, wherein the first and second forms are piecewise parallel with respect to each other. The screed has at least a first section that is coupled to a second section. The screed has a first height adjusting member with a first seat surface for slidable contact along the first form and a second height adjusting member with a second seat surface for slidable contact along the second form. The first and second height adjusting members are adjustable to set the height and angle of the at least first and second sections of the screed within the gap.
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The present invention generally relates to apparatus and methods for paving material installation and more particularly relates to an improved apparatus for arranging particulate support material and finished paving materials to a desired depth and curvature.
BACKGROUNDConstruction of quality walkways, driveways, patios, pool decks, retaining walls and footers, garden perimeters, and other similar structures is a labor-intensive process, typically requiring a number of steps, each step subject to stringent quality and performance requirements. Failure to meet set standards can be frustrating and costly, often causing rework and accompanying delays.
Using conventional construction methods, a trench is first prepared to a depth that allows for specified thicknesses of particulate substrate material that serves as a base, such as gravel, small stones, and sand. This base, in turn, supports the finished paving materials at the proper height, usually at or near ground level. Finished paving materials that are then placed upon the base can include paving blocks, stones, or bricks, or may include poured concrete or other materials. The width of the trench is significantly larger than the width of the finished walkway or other structure due to the need to provide sufficient space for forms to be inserted, manipulated and supported along the sides of the trench. Requiring time and effort that are not seen in the finished product, the process for providing the needed excess width, termed over-digging by those skilled in the construction arts, is inherently wasteful.
To assist in the substrate lay-down process, forms inserted on both sides of the trench are used to contain the particulate substrate materials and also provide a reference for arranging the finished paving material. There are many types of forms that can be used, including wood, plastic and metal forms. Wooden forms can warp undesirably and are not generally reusable, flexible, or easy to install. Plastic forms serve only in lightweight applications and are not sturdy enough to withstand the rigors of the construction environment and not rigid enough to contain heavy materials or bear the weight of a screed. Metal forms are heavy, costly to replace, troublesome to assemble, and relatively inflexible, requiring careful cleaning after use to remove any affixed concrete.
The forms are anchored in place in a number of ways, using devices such as wooden stakes, rebar, or metal stakes devised for the purpose of anchoring forms so that they remain in place as the structure is assembled. Forms are fastened to the anchors using fasteners such as clips, nails, and spacers, for example.
Leveling the forms along any section of a walkway or other structure can be a difficult task. Mistakes or tolerance errors can be additive, further complicating the leveling process.
Once the forms are set in place, the trench or gap is leveled. The term “level” does not imply that the surface of the trench need be completely flat; the term “level” is used to denote creating a smoothed continuous surface without significant high or low areas to allow depositing a layer of substrate at an essentially uniform depth.
When the dirt in the trench has been leveled, the particulate material is deposited between the forms and also leveled. To achieve a uniform depth of material, the substrate material is typically tamped down with a vibratory plate compactor or by a hand compactor. In practice, application and leveling of the substrate material is accomplished by dumping or by sifting the material into the prepared trench from wheelbarrows or other construction machinery such as front loaders. The volume of material that is dumped at any one time is calculated to spread somewhat evenly and reduce excessive raking and handling.
Using the example of a walkway, gravel is deposited as a first or substrate layer. This is then spread and leveled. This process can begin and be assisted with construction machinery, but, as it progresses, typically requires hand leveling with rakes and screed bars to the desired depth. To provide a solid base, the gravel is tamped down with a vibratory plate compactor or by a hand compactor. The cycle of depositing material, spreading, and tamping is repeated with stone dust and sand or other particulates as required, until the surface is properly conditioned for bricks or other finish materials. When all the desired layers are in place, the finished layer of paving blocks, bricks or concrete is put in place to complete the walkway.
Although the process of surface preparation for a walkway or other structure is straightforward, the preparatory steps to prepare the support substrate can be challenging. In practice, these steps are often redone, since accurate leveling at the desired depth for each layer is difficult. Thus, there is a need for improved apparatus and methods for preparation and conditioning of a support base for walkways, driveways, patios, pool decks, retaining walls and footers, garden perimeters, masonry, and other similar structures.
Proposed solutions for installation of materials for a walkway or other structure appear to be less than satisfactory. For example:
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- (i) U.S. Pat. No. 6,866,239 to Miller et al. discloses a form assembly for forming a concrete structure during drying of the concrete. The form assembly is an elongated plastic form having a front wall for engaging the concrete, and a rear wall. The front wall is spaced apart from the rear wall to define a pocket for receiving at least one connecting member. The connecting member is secured in the pocket to project a distance beyond an end of the form. A slidable stake holder may also be provided to slide in a C-shaped pocket in the form. The stake holder has right and left flanges that abut against or engage the rear wall. At least one preformed nail hole is provided in each of the right and left flanges. The forms do not indicate desired depth of materials. Connecting members secured in the pockets render the form inflexible at the joint between forms. Unfortunately, the distance from the front wall of the form to the aperture in the sliding stake holder for holding a stake is fixed, making it difficult to set distance between forms on opposite sides of the walkway, complicating lateral placement of the form with the stake accurately placed. Additionally, the sliding stake holder is not fixably engaged with the form by a connector screw or clamp; as a result, sliding, possible while particulate materials are being added between forms, can result in errors.
- (ii) U.S. Pat. No. 7,131,624 to Bogrett teaches flexible forms for creating landscape edging. However, stakes or positioning brackets used to secure the forms are not reusable, and additional spacers are needed to maintain the distance between forms, making it difficult or impractical to place paving blocks. Joining extensions are created from the same material as the forms and are not intended to be reusable and do not appear to facilitate accurate longitudinal adjoining of forms.
- (iii) U.S. Pat. No. 6,021,994 to Shartzer teaches a flexible form for use in pouring concrete. Rigid core members are added to maintain strength but removed when flexibility is desired. Stakes protrude through the forms and connection to the form is made only via the rigid core members with nails, complicating the task of positioning the forms. Since the rigid core members are removed when the forms are bent, however, securing the stakes to the form is not possible.
- (iv) U.S. Pat. No. 4,340,351 to Owens teaches a screed fabricated in modular fashion from a plurality of interconnected, separable frame units. Modular sections forming the screed can be connected to provide a convex or concave screed depending on the shape of the desired surface. However, the screed formed from modular sections is a complicated assembly, difficult to fabricate, and does not provide adjustment appropriate to the desired depth of layers of particulate material.
There exists a need to improve the quality of tools used in creating layers of material for supporting particulate and finished paving materials which eliminate much of the expertise required for substrate preparation and reduce unnecessary rework.
SUMMARY OF THE INVENTIONEmbodiments of the present invention address the need for improved apparatus and methods for depositing and preparing surface particulate, stone, bricks, concrete, and related materials for paving installation.
In accordance with one aspect of the present invention there is provided an apparatus for installation of paving materials, the apparatus comprising a screed that is configured to extend across a gap between first and second forms, wherein the first and second forms are substantially piecewise parallel with respect to each other, wherein the screed has at least a first section that is coupled to a second section, and wherein the screed has a first height adjusting member with a first seat surface for slidable contact along the first form and a second height adjusting member with a second seat surface for slidable contact along the second form and wherein the first and second height adjusting members are each adjustable to set the height and angle of the at least first and second sections of the screed within the gap.
From an alternate aspect, embodiments of the present invention provide an apparatus for installation of paving materials, the apparatus comprising a screed that is configured to extend across a gap between first and second forms, wherein the first and second forms are substantially piecewise parallel with respect to each other, wherein the screed has:
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- (i) at least a first section that is coupled to a second section;
- (ii) a first height adjusting member within a first cavity and having a first seat surface for slidable contact along a first contact surface of the first form;
- (iii) a second height adjusting member within a second cavity and having a second seat surface for slidable contact along a second contact surface of the second form and wherein the first and second height adjusting members are each adjustable to set the height and angle of the at least first and second sections of the screed within the gap;
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- (iv) at least one bucket accepting coupling, wherein the at least one bucket accepting coupling has a slot that extends along the screed in a length direction for accepting a portion of a lip of a bucket for an earth-moving apparatus.
Advantageously, embodiments of the present invention provide a solution for paving installation that is readily scalable for walkways and other structures of various widths and using a wide range of particulate and finished materials.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.
Embodiments of the invention will now be described with reference to the drawings in which:
Figures shown and described herein are provided in order to illustrate key principles of operation and fabrication for an apparatus according to various embodiments and a number of these figures are not drawn with intent to show actual size or scale. Some exaggeration may be necessary in order to emphasize basic structural relationships or principles of operation.
In the context of the present disclosure, terms “top” and “bottom” or “above” and “below” are relative and do not indicate any necessary orientation of a component or surface, but are used simply to refer to and distinguish opposite surfaces or different portions of a material. Similarly, terms “horizontal” and “vertical” may be used relative to the figures, to describe the relative orthogonal relationship of components, for example, but do not indicate any required orientation of components with respect to true horizontal and vertical orientation.
Where they are used, the terms “first”, “second”, and so on, do not necessarily denote any ordinal or priority relation, but are used for more clearly distinguishing one element or time interval from another. There are no fixed “first” or “second” elements in what is taught herein; these descriptors are merely used to clearly distinguish one element from another similar element in the context of the present disclosure.
In the context of the present disclosure, the term “paving materials” relates to any of a number of types of finish material, such as bricks or paving tiles, or particulate material that is laid down and formed as part of a base for a tiled or paved surface or wall structure. The paving material may be dry, as in the case of bricks, sand, gravel, or crushed stone, or may be mixed with a liquid, as in the case of concrete, asphalt, or other material. Forming of the material may include various operations used to distribute, shape, condition, or compress the particulate materials, such as spreading, tamping, leveling, rolling, wetting, drying, troweling, and other operations, for example.
In the context of the present disclosure, the term “oblique” describes an angular relationship that is not parallel or normal, that is, other than an integer multiple of 90 degrees. In practice, two surfaces are considered to be oblique with respect to each other if they are offset from parallel or normal by at least about +/−10 degrees or more. Similarly, a line and a plane are considered to be oblique to each other if they are offset from parallel or normal by at least about +/−10 degrees or more.
In the context of the present disclosure, the term “piecewise parallel” has its standard meaning, indicating that two structures may follow the same curved path and extend substantially in parallel at any point along the path. Forms that are on opposite sides of a curved walkway are piecewise parallel when a line that is substantially in parallel with the edge of each form can be extended between the forms.
Embodiments of the present invention address the problem of paving material installation using a combination of a configurable screed and flexible plastic forms that are straightforward to setup, adjust, and use in a particular application. According to an embodiment of the present invention, and shown in
Forms 100 and 105 can be manufactured in preformed lengths, typically 20, 16, 12, 10, or 6 feet long, and can be cut to any length. According to an embodiment of the present invention, forms 100 and 105 are fully pliable, lightweight, and easy to measure and cut. A flange 150, along the base of forms 100 and 105, provides additional strength and a base surface for resting forms 100 and 105 on the ground.
A back side 130 of forms 100 and 105 faces away from the particulate and other paving materials. Back side 130 has channels 140 that allow connection and staking of forms 100 and 105.
In
In practice, connector assembly 200 secures forms 100 and 105 to anchors 290. For the purpose of example and not by way of limitation, a preferred method of securing form 100 in place is described. Clamp 205 is first set loosely on anchor 290. Anchor 290 is then pounded into the earth such that it is solidly secured and has minimal opportunity to move but still accessible to connector assembly 200. Rotary T-slot bolt 215 is inserted into channel 140 and handle 235 is rotated so that head 217 of rotary T-slot bolt 215 is captured inside channel 140. Wing nut 230 is rotated to pinch channel 140 between head 217 of rotary T-slot bold 215 and washer 220, securing connector assembly 200 to form 100. When form 100 is set in the desired position, tightening knob 210 is rotated, which tightens clamp 205, fixing the vertical position of form 100. Tightening knob 210 also fixes barrel clamp 207 to clamp tube 225, fixing position of form 100 or 105 on horizontal axis 180. Prior to rotating tightening knob 210, barrel clamp 207 can slide on clamp tube 225 so that the horizontal position of form 100 can be adjusted relative to the position of anchor 290.
The positional flexibility of connector assembly 200 provides substantial time savings over prior art connectors. Connector assembly 200 is easily adjusted in all three axes relative to forms 100 and 105. Because head 217 of rotary T-slot bolt 215 can be inserted and secured anywhere along channel 140, connector assembly 200 can move freely along longitudinal axis 160 toward the position of anchor 290. Clamp 205 can be set anywhere along the height of anchor 290, simplifying vertical adjustment of form 100 or 105. Advantageously, anchor 290 can be driven at an angle other than vertical, and clamp 205 will rotate on clamp tube 225 to accommodate the nonvertical angle of anchor 290. This can happen, for example, where the paving site has rocks or other impediments. Barrel clamp 207 is free to slide along a portion of the length of clamp tube 225, so that adjusting the distance along horizontal axis 180 between opposite forms 100 or 105 is facilitated. The positional flexibility of connector assemblies 200 provides time and labor savings by eliminating tedious resetting of anchors 290 for stabilizing the forms.
Referring to
Outside ends 335 of sections 310 and 330, away from central section 320, have wings or projections 342. Projections 342 extend beyond screed body 305 and terminate in an open vertical channel 350 that provides a cavity with a square opening in the embodiment shown. Height selection block 355 fits into open vertical channel 350, and is fixed in position within the cavity provided by open vertical channel 350 by a bolt 360 which passes through holes 365 in open vertical channel 360 and also passes through one of holes 370 in height selection block 355, shown in
Note that seat surface 358 as shown in
Still referring to
In places where a flat profile would be undesirable, such as a walkway between buildings, the arrangement of
Screed sections 320 and 322 have tongue protrusions 325 at one end and sleeve openings 327 at the opposite end as fittings for joining to additional sections. Protrusions 325 are configured to fit into openings 327 for each section, to provide a coupling arrangement that is similar to a mortise and tenon joint familiar to woodworkers. Note that screed 300 may also be manufactured with expanding sections that slide over each other, bolt or fasten together in some way, or in some other combination that allows coupling of screed sections together to allow variable screed length and curvature profile.
In operation for forming a supporting base, screed 300 is dragged across each layer of particulate material that is spread between the forms, producing a uniform, compact layer. Screed 300 can be dragged by hand for smaller projects. For larger projects, screed 300 can be moved along with a bucket attachment that creates compressive downward force; this type of operation can use a walk-behind device such as a skid steer Dingo TX 427 Wide Track from Toro Corporation, Bloomington, Minn., or use operator-driven machinery such as a Skid Steer Loader S100 from Bobcat Co., division of Doosan Infracore International, Seoul, South Korea. Multiple passes with screed 300 can be employed for a particular layer since compacting and addition of additional particulate material can be necessary for achieving a base with the proper characteristics for supporting the finished layer.
Some installations, for example, require a two-inch base for concrete projects.
In
Paving stone projects often require two base layers, as shown in
Steps for installation of a paving stone walkway using an embodiment of the present invention are given in the flow chart shown in
Referring to
Continuing with the
When one form 105 is secured in place, then the complementary, piecewise-parallel form 105 along the opposite edge of the walkway is anchored by the same method. Note that the position of form 105 can be easily adjusted to the specifications of the job because connector assemblies 200 are readily adjustable in a leveling step 625. For example, if the forms 105 on either side of the walkway are to be level with one another, the relative heights of the forms can be quickly adjusted to level by loosening tightening knob 210, adjusting the height of form 105, and then re-tightening tightening knob 210. Note that screed 300 can be placed between forms 105 to assist in making sure that the distance between forms 105 is proper. When the walkway or other structure is straight, the task of adjusting connector assemblies 200 so that opposing forms 105 are parallel is straightforward. When the walkway to be created is curved, adjusting connector assemblies 200 so that opposing forms 105 are piecewise parallel is facilitated.
In a connector insertion step 630, section connectors 260 are inserted into channels 140 of the form 105 that has been secured to the earth, and to each additional form 105 that is moved into an adjacent position. Additional adjacent form 105 butts up against form 105 which is already secured to the earth. Note that butting the ends of forms 105 to each other and connecting the forms 105 by tightening four armed knobs 280 in a connection step 635 assists in positioning additional adjacent form 105 when the previously described process for securing forms 105 to the earth is repeated. As forms 105 are added, additional adjacent forms 105 tend to follow the same line that is established by the top or bottom of the initially installed form 105. In this way, the tedious task of leveling or contour filling is minimized. In common practice, a string line or laser is used to establish the top position of forms 105. In contrast to using wood or metal forms, the easy vertical positioning of forms 105 provides a simplified mechanism that can readily match a string line or laser leveling device. Also, use of forms 105 prevents the need for large numbers of anchors, as is necessary for use with wood forms due to warping, bowing and twisting.
Continuing with the sequence in
A disassembly step 670 then follows, in which the forms structure is systematically removed. Connector assemblies 200 are loosened by rotating two armed knob 210, four armed knob 230 and two armed knob 235, and then removed, disconnecting forms 105 from anchors 290. Forms 105 are removed from the ground. Sectional connectors 260 are removed. Anchors 290 are then removed. Backfilling the area of overdigging occurs in a backfill step 690 and the installation is complete.
Screed 300 can be moved along the length of contact surface 108 of forms 100 or 105 by hand. Alternately, screed 300 can be moved using machinery, which is advantageous where the width between forms 100 or 105 is large, for example, when this width is 4 feet or more. Because some projects dictate that screed 300 be moved by machinery, clamps 345 of screed 300 have bucket accepting features 347 for insertion of a bucket for equipment often used in construction. Once the lip of the bucket is inserted into slot 348 of bucket accepting features 347, the front-loader or other piece of mobile earthmoving apparatus drags the screed along the top of the forms 100 or 105 to achieve the desired profile for deposited particulate material. Note that the length of screed 300 can be adjusted by using sections of different length dimensions, or by adding additional sections. In practice, embodiments of the present invention are particularly well suited for use for widths between 15 inches and 20 feet; however, embodiments of the present invention are not limited to those dimensions.
Use of forms 100 or 105, connector assemblies 200, section connectors 260 and screed 300 reduces the time necessary for preparation of layers supporting the finished materials, and in the case of concrete, can reduce the time required for installing that finished material. Due to the accurate leveling of large amounts of material that is placed between the forms 100 or 105, tedious and error-prone hand raking can be greatly reduced or eliminated. Also, placing material by hand with multiple wheelbarrow loads may no longer be necessary. Construction crews can substantially cut the cost and time of paving projects because the forms 100 or 105, connector assemblies 200, section connectors 260 and screed 300 are reusable, light weight, and easy to configure and manipulate. Thus, crews using the described solution can produce a superior product that meets or exceeds industry standards with reduced time and labor. Screed 300 can be used by hand or with any of a number of types of earth-moving apparatus and related equipment that have a blade or bucket, including systems that seat an operator and walk-behind systems, for example.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention as described above, and as noted in the appended claims, by a person of ordinary skill in the art without departing from the scope of the invention. The invention is defined by the claims.
Claims
1. A screed apparatus for paving materials comprising:
- a modular screed body that is horizontally extended by coupling at least a first and a second screed section together, wherein the first screed section has a tongue protrusion and the second screed section has a corresponding sleeve opening that fits over the tongue protrusion for coupling the first and second screed sections,
- wherein at least the first screed section has a vertically extending projection along an outside end,
- wherein the projection along the outside end supports a vertical channel that extends beyond the outside end of the first screed section;
- and
- a height selection block that fits into the vertical cavity and fastens within the vertical cavity.
2. The screed apparatus of claim 1 wherein
- the tongue protrusion is a first tongue protrusion,
- the sleeve opening is a first sleeve opening,
- the vertically extending projection is a first vertically extending projection,
- the outside end is a first outside end,
- the vertical channel is a first vertical channel,
- the height selection block is a first height selection block,
- and further comprising a third screed section that couples to a corresponding second tongue in the second screed section by a second corresponding sleeve opening in the third screed section that fits the second tongue protrusion,
- wherein the third screed section has a second vertically extending projection along a second outside end,
- wherein the second projection along the second outside end supports a second vertical channel that extends beyond the second outside end of the third screed section;
- and
- a second height selection block that fits into the second vertical cavity and fastens to a selectable height position within the second vertical cavity.
3. A screed apparatus for paving materials comprising:
- at least a first elongated screed end section and a second elongated screed end section, wherein each elongated screed end section is substantially rectangular in shape and has a vertically extending projection along an outside end,
- wherein the projection along each outside end supports a vertical channel that extends beyond the outside end of the screed section;
- a height selection block at each outside end, wherein the height selection block fits into the corresponding vertical cavity and fastens to a selectable height position within the vertical cavity by a fastener;
- and
- one or more central screed sections that fit between the end sections to elongate the screed apparatus,
- wherein one or more of the screed sections is configured to couple to an adjacent screed section by a tongue protrusion formed on the screed section that is sized to fit into a corresponding sleeve opening formed in the adjacent screed section.
4. The screed apparatus of claim 3 wherein the fastener is a bolt extended through a corresponding hole in the vertical cavity.
5. The screed apparatus of claim 3 wherein the fastener is a clamp.
6. The screed apparatus of claim 3 wherein one or more of the central screed sections is preformed to impart a convex surface profile to a bottom surface of the screed apparatus.
7. The screed apparatus of claim 3 wherein one or more of the central screed sections is preformed to impart a concave surface profile to a bottom surface of the screed apparatus.
8. The screed apparatus of claim 3 wherein one or more of the height selection blocks is vertically adjustable to adjust screed height within a gap.
9. The screed apparatus of claim 3 wherein each of the screed end and central screed sections are molded.
10. The screed apparatus of claim 3 further comprising one or more external clamps that affix one or more of the screed sections to each other.
11. The screed apparatus of claim 10 wherein the one or more external clamps further comprise a bucket accepting coupling.
12. A screed apparatus for paving materials comprising:
- at least a first elongated screed end section and a second elongated screed end section, wherein each elongated screed end section is substantially rectangular in shape and has a vertically extending projection along an outside end,
- wherein the projection along each outside end supports a vertical channel that extends beyond the outside end of the screed section;
- a height selection block at each outside end, the height selection block having a plurality of holes, wherein the height selection block fits into the corresponding vertical cavity and fastens within the vertical cavity by a fastener extended through one of the plurality of holes;
- and
- one or more central screed sections that elongate the screed apparatus and that are preformed to impart a curved profile to a bottom surface of the screed apparatus,
- wherein one or more of the screed sections is configured to couple to an adjacent screed section by a tongue protrusion formed on the screed section and sized to fit into a corresponding sleeve opening formed in the adjacent screed section.
13. The apparatus of claim 12 wherein the bottom surface of at least one of the one or more central screed sections is curved.
Type: Application
Filed: Jun 13, 2016
Publication Date: Sep 29, 2016
Applicant: RFVC Associates, Inc. (Fairport, NY)
Inventor: Jason Scott Ganey (Edgewater, MD)
Application Number: 15/180,128