Paver locking apparatus and method

Abstract

The present invention is directed to a paver edge restraint system for reducing shifting of a paver units making up a paved surface having one or more edge restraints installed along at least a portion of the periphery of the paved surface. The paver edge restraint system includes at least one peripheral edging member, at least one edging securement member for holding the at least one peripheral edging member to the ground, at least one paver retention strap that extends underneath a plurality of paver units constituting a portion of the paved surface, and at least one clamping unit mounted on the at least one peripheral edging member for securing and tightening the at least one strap to maintain the joint integrity of the plurality of paver units installed above and adjacent to the at least one strap.

Claims

1. A paver edge restraint system for reducing shifting of paver units making up a paved surface having one or more edge restraints installed along at least a portion of a periphery of the paved surface, the paver edge restraint system, comprising: at least one peripheral edging member; at least one edging securement member for holding the at least one peripheral edging member to a ground surface; at least one paver retention strap that extends underneath a plurality of the paver units constituting a portion of the paved surface; and at least one clamping unit mounted on the at least one peripheral edging member for securing and tightening the at least one strap to maintain joint integrity of the plurality of paver units installed above and adjacent to the at least one strap, the at least one clamping unit having a housing including a back wall having a substantially planar outer surface dimensioned to contact an outer surface of the at least one peripheral edging member.

2. The paver edge restraint system of claim 1 wherein the at least one clamping unit further includes a clip portion extending from a portion of the back wall of the housing of the clamping unit for mounting the clamping unit on the at least one peripheral edging member.

3. The paver edge restraint system of claim 1 wherein the at least one peripheral edging unit comprises a first peripheral edging unit and second peripheral edging unit located on opposed peripheral edges of the paved surface, the at least one clamping unit comprises a first clamping unit mounted on the first peripheral edge member and a second clamping unit mounted on the second peripheral edge member, and the at least one strap has a first end attached to the first clamping unit and a second end attached to the second clamping unit.

4. The paver edge restraint system of claim 1 wherein the clamping unit further comprises a strap retention shaft rotatably mounted on the clamping unit, the strap retention shaft being dimensioned for receipt of a first end of the at least one paver retention strap and whereby rotation of the strap retention shaft tightens the at least one paver retention strap when attached thereto.

5. The paver edge restraint system of claim 4 wherein the strap retention shaft is operably coupled to a ratchet wheel having a plurality of teeth for maintaining rotational position of the at least one paver retention strap after being tightened to maintain the joint integrity of the plurality of pavers constituting the portion of the paved surface.

6. The paver restraint system of claim 5 further comprising a pawl arm pivotally mounted to the at least one clamping unit and dimensioned to engage the plurality of teeth of the ratchet wheel.

7. A method of installing a paver edge restraint system to maintain a desired joint integrity between paver units making up at least a portion of a paved surface, the method comprising the steps of: laying a sub-base of compacted materials to support a plurality of the paver units; trimming a paver restraint strap material to a length which approximates a distance between at least one first clamping unit to be located adjacent to a first planned lateral paved surface edge and a strap receiving member located nearer a second planned lateral paved surface edge; laying the measured, trimmed paver restraint strap material over the installed sub-base; installing the plurality of pavers between the first planned lateral edge and second planned lateral edge with a portion of at least one of the pavers being installed above the measured, trimmed paver restraint strap; securing a first lateral edge restraint to a ground surface adjacent to the first lateral edge; securing a respective said clamping unit to the first lateral edge restraint; securing a first end of the measured, trimmed paver restraint strap to the respective clamping unit; securing a second end of the measured, trimmed paver restraint strap to the strap receiving member; and tightening the measured, trimmed paver restraint strap in order to cause the first clamping unit to press against the first lateral edge restraint in order to maintain the desired joint integrity between the paver units making up at least the portion of the paved surface.

8. The method of installing a paver edge restraint system of claim 7 wherein the strap receiving member is a second clamping unit and the second planned lateral paved surface edge has a second lateral edge restraint located adjacent thereto and wherein the step of tightening the measured trimmed paver restraint strap causes the second clamping unit to press against the second lateral edge restraint.

9. The method of installing a paver restraint system of claim 7 wherein the strap receiving member is an anchor plate having a belt securement aperture.

10. The method of claim 7, wherein the step of securing the clamping unit to the first lateral edge restraint comprises placing a clip portion of the clamping unit on top of the edge restraint.

11. The method of claim 7, wherein the strap receiving member is a second clamping unit.

12. The method of claim 7, wherein the strap receiving member is an anchor plate.

13. The method of claim 7, further comprising the step of providing a clamping unit with a housing and a cover for enclosing a space within the housing.

14. The method of claim 7, further comprising the step of assembling a clamping unit comprising: a housing defining a clamping unit interior, the housing having a first sidewall, second side wall, back wall, and bottom wall, the back wall of housing having a substantially planar outer surface for contacting a surface of the at least one edge restraint; a strap retention shaft rotatably mounted between the first sidewall and second sidewall within the clamping unit interior; a cover for enclosing the clamping unit interior; and a clip portion extending from the back wall of the housing for securing the clamping unit to the at least one edge restraint.

15. The method of claim 7, further comprising the step of assembling a paver edge restraint kit comprising a length of elongated paver restraint strap and a plurality of clamping units each having (i) a securement member for mounting each of the clamping units to a paved surface edging restraint, and (ii) a rotatable shaft with a slot dimensioned to receive one end of the paver restraint strap, the rotatable shaft having a lever receipt member dimension for engagement with a clamping lever to cause rotation of the shaft and thereby tightening of a strap mounted to the rotatable shaft to retain the joint integrity of the paver units of a paved surface.

16. The method of claim 7, further comprising the step of providing a moisture resistant, biodegradation resistant and abrasion resistant paver restraint strap material.

17. The method of claim 7, wherein the step of tightening the measured, trimmed paver restraint strap comprises rotating a strap retention shaft of the clamping unit.

18. The method of claim 17, wherein the step of tightening the measured, trimmed paver restraint strap comprises maintaining the rotational position of the strap retention shaft using a ratchet wheel coupled to the strap retention shaft.

19. The method of claim 7, further comprising the step of providing a clamping unit with a back wall, wherein a lower portion of the back wall of the housing defines a strap entrance dimensioned to allow the paver restraint strap to pass through.

20. The method of claim 19, further comprising the step of threading the paver restraint strap through the strap entrance.

21. The method of claim 19, further comprising the step of providing a lever receipt member on the clamping unit and wherein the step of tightening includes rotating the strap retention strap with a lever inserted in the lever receipt member.

Description

DESCRIPTION OF THE DRAWINGS

(1) The organization and manner of the structure and function of the invention, together with the further objects and advantages thereof, may be understood by reference to the following description taken in connection with the accompanying drawings, and in which:

(2) FIG. 1 is a top plan view of an edging restraint system in accordance with a first embodiment of the invention;

(3) FIG. 2 is a side cross-sectional view of an edging restraint system in accordance with the embodiment of FIG. 1;

(4) FIG. 3 is an enlarged fragmentary perspective view of a clamping unit with the cover removed in accordance with the systems the invention;

(5) FIG. 4 is an enlarged rear perspective view of the clamping unit with the cover closed in accordance with FIG. 3;

(6) FIG. 5 is an enlarged, side perspective view of the clamping unit of the invention shown in FIG. 3;

(7) FIG. 6 is a side perspective view of a clip for use in the clamping unit of the invention shown in FIG. 3;

(8) FIG. 7 is an expanded perspective view of a ratchet, pawl, and shaft of the clamping unit of the invention shown in FIG. 3;

(9) FIG. 8 is a top plan view of an edge restraint system for use abutting or building in accordance with a second embodiment of the invention;

(10) FIG. 9 is a perspective view of a spike and anchor plate in accordance with the second embodiment of the invention shown in FIG. 8;

(11) FIG. 10 is a top plan view of an edge resistant installation kit in accordance with a third embodiment of the invention.

DETAILED DESCRIPTION

(12) A first embodiment of the system of the invention is illustrated in FIGS. 1-4, the paver retention system 20 impedes paver joint shifting and maintains paver pattern integrity for a paved surface 24a comprised of individual pavers 28. The paved surface 24a has a pair of lateral edging units 26a, 26b which are secured to the ground by a plurality of spaced apart edging spikes 27. Four straps 22a-d are shown in FIG. 1 that extend underneath rows of pavers 28 between four pairs of clamping units 40a,b. Each of the straps 20a-d are laid underneath parallel rows of pavers 28 and spaced apart by about six paver edging spikes 27 which hold down the edging strips 26a,b. Preferably, the adjacent straps 22a-d are spaced apart of between about two feet and about four feet.

(13) Once the straps 22a-d are installed beneath pavers, the straps 22a-d will be exposed to moisture, freeze thaw cycles, and may be subject to a biodegradation by mold and/or bacteria for a period of multiple years to multiple decades. The straps 22a-d can be made from any woven or non-woven strap material with sufficient strength, abrasion resistance, biodegradation resistance, and moisture tolerance such as, for example, a woven polyester cord, polyester composites, or woven polypropylene. The preferred paver retention strap material is a web of woven polyester material having a width between about (0.75) of an inch and about two inches provided to the paver installer on a spool (not shown) in spool lengths between 100 and 500 feet. However, paver retention strap widths as narrow as 0.5 inches in width may be used in paver installations where cost constraints are paramount. The edging units 26a-b are preferably made from polyvinylchloride (PVC) and have vertical wall 23 for contacting the outer edge of the peripheral pavers 28a-h and a flange 25 extending from the bottom edge of the edging unit 26. The flange 25 has a plurality of apertures 29 for receipt of pave edging spikes 27.

(14) As best seen in FIG. 2, each of the clamping units 40a,b bracket the edging units 26a-b, which in turn bracket outer edge of the perimeter pavers 28a,h on the end of each of the rows of pavers. The pavers 28 are installed on a conventional paver base system 33 which typically includes a course sand layer 30, compacted aggregate layer 32 and a compacted subbase layer 34. Each of the paver retention straps 22a-b extend between and are secured to the clamping units 40a,b before being tightened between the clamping units 40a,b.

(15) As shown in FIGS. 4-8, the clamping unit 40 includes a cover 41, a housing 42 having an axle receipt aperture 49, a pawl arm 44 which registers against the teeth portion 43 of a ratchet wheel 46, and a shaft 48 which passes through ratchet wheel 46 and shaft aperture 49. The housing 42 has a first sidewall 35, second side wall 36, front wall 37, back wall 38, and bottom wall 39. The back wall 38 of housing 42 has a substantially planar outer surface 53 for contacting the vertical wall 23 of the peripheral edge restraint 26. The shaft 48 includes a slot 47 which is dimensioned to receive one end of the strap 22. The end portion of the shaft 48 includes a series of apertures 45 which are dimensioned to receive the terminal ends of the clamping lever 55. The clamping lever 55 rotates the shaft 48 so that the teeth 43 of the ratchet wheel 46 are engaged by pawl arm 44 to prevent the tightened paver retention strap 22 from loosening after installation of a paver retention strap 22 under the pavers 28. The shaft 48 is rotated by a clamping lever 55, which detachably mounts through the aperture 45 formed in end of axle 48. The clamping unit 40 further includes a clip member 52 for mounting the clamping unit 40 to the vertical portion of the edge restraint 26. Housing 42 further includes cover mounting ledges 35a, 36a, and 37a formed in first sidewall 35, second sidewall 36, and front wall 37. The cover 41 is dimensioned to rest upon cover mounting ledges 35a, 36a, and 37a. Cover 41 further includes a clip cut out 41a to accommodate entry of the clip 52 into the interior of the housing 42 and a tab 54 for securing the cover 41 to the housing at the indent 59 formed in the front wall of the housing 42. The tab 54 and indent 57 shown in FIGS. 4 through 8 are relatively small but can be strengthened by elongating both tab and indent (not shown) for paver installation situations where increased housing cover strength is deemed necessary.

(16) Since the clamping units 40 of the systems of the invention 20 will be mounted to an edging restraint 26 that will typically be back filled with soil or gravel or other material and be exposed to the elements for multiple years, it is important that the components of the clamping unit 40 do not corrode or otherwise degrade for a period of years after their installation. For this reason and for cost efficiency, the preferred material for fabrication of the housing 42 is a polyvinyl chloride (PVC) resin, High Density Polyethylene (HDPE) or similar plastic resins with sufficient strength, abrasion resistance, moisture resistance, and biodegradation resistance. Alternately, housing 42 of clamping unit 40 of the invention can also be fabricated from aluminum sheet stock with a gauge of between about 10 and 18. The housing 42 and cover 41 may also be fabricated from a variety of corrosion resistant metal or metal alloy sheet stock or from ferrous metal or metal alloy sheet stock coated with a corrosion resistance coatings (galvanized metals). The clamping unit cover 41 is preferably fabricated of a similar material as the housing 42 and is preferably trimmed to size utilizing a CNC cutting tool.

(17) The shaft 48 is preferably injection molded from a strong, light plastic resin such as HDPE or PVC, but may also be fabricated from metal or metal alloy bar stocks, such as galvanized steel bar stock. Alternately, for paver installation situations where strength of the shaft is deemed to be of greater importance than minimizing cost, the shaft 48 may be cut from steel bar stock and then coated with plastic or another corrosion resistant material to prevent rust. The slot 47 and lever receipt apertures 45 are formed in the shaft 48 by either a CNC cutting tool or bar stock cutting tool, but may optionally those features may be molded into the shaft 48 by utilizing injection molding of plastic resin, or by a metal injection molding or forging process to form the shaft 48. If the shaft 48 is formed from a corrosion susceptible metal, the shaft 48 is also preferably coated with an anti-corrosion material such as zinc, zinc metal alloys, or a plastic resin after cutting process is complete. The pawl arm 44 and toothed wheel 46 may be fabricated by injection molding an HDPE or PVC resin or may also be fabricated from strong, light weight metal sheet stock and machined with a CNC cutting tool to their final dimensions and then coated with a corrosion resistant coating such as zinc, or a zinc/metal alloy. The clip member 56 may be fabricated by injection molding an HDPE or PVC resin or maybe formed from a light weight corrosion resistant metal or metal alloy sheet stock such as powder coated steel, aluminum, or galvanized steel. Since clip member 52 will be snap fit over a vertical wall 23 of an edging unit 26, the metal versions of clip member 52 are preferably fabricated from sheet stock of a resilient metal alloy such as spring steel or galvanized spring steel. The metal version clip member 52 is preferably bent into its final shape by a precision bending tool. After bending to its final shape, the metal version of clip member 52 is preferably coated with a non-corrosive coating of zinc or a zinc/metal alloy.

(18) As can be seen in FIG. 6, the clip 52 includes an upward extending portion 52a, forward extending portion 64, lip portion 58 and bottom portion 61. The size and proportions of the clip 52 can be modified to fit the most commonly utilized commercial edge restraints. The inner surface of the lip portion 58 of clip 52 is dimensioned for engaging the outer surface of the vertical wall 23 of the edging unit 26. The upward extending portion 52a of the clip 52 is dimensioned to be slightly longer than the height of the vertical sidewall 23 of the edging unit 26. The distance between the inner surface of the lip portion 58 and the upwardly extending portion 52a are dimensioned to be equal to the width of the vertical wall 23 of the edging unit 26 plus the back wall 38 of the housing 42 so that, when the clamping unit 40 is inserted onto the top of the vertical wall 23, there is a friction fit between the back wall 38, vertical wall 23 and lip portion 58. This allows for the housing 42 and remainder of the clamping unit 40 to be standardized and only the size and proportions of the clip 52 changed to accommodate edging units having taller vertical walls or thicker vertical walls. To do so, the length of forward extending portion 64 can be shortened to accommodate thinner vertical sidewalls and lengthened to accommodate thicker vertical sidewalls. Similarly, the length of the upward extending portion 52a can be lengthened to accommodate taller, edge unit vertical sidewalls and shortened to accommodate shorter, edge unit vertical sidewalls.

(19) After tightening of the paver retention straps 22 below the pavers 28 of the paved surface 24a, the clip 52 secures clamping units 40 to the edging units 26 so that the clamping units 40, tightened paver retention strap 22, and edging unit 26 all move together during a freeze/thaw cycle. This causes the pavers 28 and edging units 26 to be securely linked to each other to minimize movement of the pavers 28 relative to edging units 26 during a freeze/thaw cycle. In other words, the binding of the heavy pavers 28 by the tightened paver retention straps 22, the tight grip the clamping units 40 has on the tightened paver retention straps 22, the secure mounting of the clips 52 of the clamping units 40 to the edging units 26, and the firm engagement of the spikes 27 with the edging units 26 contributes to minimize any upward movement of the edging units 26 during freeze/thaw cycles. Furthermore, to the lesser extent that the pavers 28 and edging units 26 of the invention might move upward due to subsurface ice formation, after the subsurface ice melts, the pavers 28 will settle down to their original level due to the force provided by foot or vehicle traffic passing over the pavers 28 or due to the weight of the pavers 28 themselves. Since the edging units 26 of the system of the invention are securely linked to the pavers 28 via the clamping units 40 and paver retention straps 22, the downward movement of the pavers 28 (with their joint integrity maintained by the tightened paver retention straps 22) after a subsurface ice thaw helps to pull the edging units 26 back down into their original position.

(20) As best illustrated in FIG. 7, to assemble a clamping unit 40, the shaft 48 is inserted through wheel 46 with the exterior flattened surface 48a of the shaft 48 aligned with the flattened interior surface 46a of the wheel 46. The ratchet arm 44 includes a pin receipt aperture 44a for receipt of ratchet mounting pin 44b. The shaft 48 is secured on one end once inserted through aperture 49 of housing 42 by cotter pin 48b which is inserted through pin aperture 48c. On the other end, the increased diameter of the lever receipt ring 45a engages the exterior surface of second sidewall 36 upon complete insertion of the shaft 48 through the axle receipt aperture 49. The clamping lever 55 is preferably formed from steel bar stock which is tapered on the engagement end 56. The engagement end 56 is formed with a CNC cutting tool and is preferably bent into its final configuration with a precision bending tool.

(21) FIG. 8 shows a second embodiment of the invention for stabilizing a paved surface 60, which abuts a building foundation 70 on two of its peripheral sides. Since the two sides of the paved surface are in contact with a solid concrete foundation 70a,b only a single clamping unit is used per paver retention strap 22c which is located adjacent to the edging strips 26c. Accordingly, the paver retention straps 22c of this embodiment of the invention pass underneath the rows of pavers 28c and are secured on the end closest to the foundation 70a,b by an anchor plate 62 toward the middle of the paved surface 60. The anchor plate 62 can be held in place by the weight of the group of pavers that cover the anchor plate 62. As shown in FIG. 9, anchor plate 62 may include an aperture 62a for receipt of an anchor plate spike 63 to help to secure the anchor plate 62 to the paver base. The anchor plate 62 includes an anchor plate slot 67 for receipt of the one end of the paver retention strap 22c. The paver retention strap 22c is secured to the anchor plate 62 by anchor plate spike 63.

(22) The process of installing a paver edge restraint system including the steps of laying the paver base of compacted materials to support the pavers. After the paver base 33 is installed, a paver retention strap material is measured and then trimmed to a length that matches the distance between the first clamping unit 40 and the second clamping unit 40 which are situated adjacent to the first edge restraint unit 26 and the second edge restraint unit 26. Next, the trimmed paver retention strap material is placed over the installed paver base 33 with the two ends of the paver retention strap 22 extending past the planned lateral edges of the paved surface 33. This typically means the two ends of the trimmed straps 22 extend between about 8 and about 10 inches past the lateral edges of the installed paver base 33. After the pavers 28 are installed above the trimmed paver retention strap, the first edge restraint unit 26 and second edge restraint unit 26 are secured to the ground adjacent to the paver base 33 along the lateral edges of the paved surface. The paver retention strap 22 is then secured to one of the clamping unit 40 by inserting the paver retention strap 22 through slot 47 in the shaft 48 and turning the shaft 48 until the paver retention strap 22 wraps back around onto itself. The clamping unit 40 is secured to the edge restraint units 26. The pavers 28 are then installed over the paver base 33 in between the edge restraint units 26 with a portion of the pavers 28 being installed over the paver retention strap 22. The paver retention strap 22 is tightened by inserting lever 55 in lever receipt aperture 45 and pushing or puling on the handle end 57 of lever 55 to cause shaft 48 to rotate thereby tightening the paver retention strap 22 between the first and second clamping units 40 in order to maintain the desired joint integrity.

(23) The process of installing a paver edge restraint system with a single clamping edge unit as shown in the embodiment of the invention in FIG. 8 is similar to the process described immediately above with the exceptions discussed below. The paver retention strap material is measured and then trimmed to a length that is slightly longer than the distance between the planned location of the first clamping unit 40c and the planned position of the anchor plate 62. The first clamping unit 40c is situated laterally adjacent to the planned position of the first edge restraint unit 26c. Next, the measured trimmed paver retention strap material is placed over the installed paver base with the first end of the paver retention strap 22c extending past the planned position of the edging unit 26c and the second end of the paver retention strap 22c is attached to the anchor plate 62 by threading through the slot 67 and wrapping it around the anchor plate 62. After the pavers 28c are installed above the trimmed paver retention strap, the first edge restraint unit 26c is secured to the ground adjacent to the paver base along the edge restraint unit 26c of the paved surface 24c. The paver retention strap 22c is then secured to the single clamping unit 40c by inserting the paver retention strap 22c through slot 47 in the shaft 48 and turning the shaft 48 until the paver retention strap 22c wraps back around onto itself. The single clamping unit 40c is secured to the edge restraint unit 26c. The paver retention strap 22c is tightened by inserting lever 55 in lever receipt aperture 45 and pushing or puling on the handle end 57 of lever 55 to cause shaft 48 to rotate thereby tightening the paver retention strap 22c between the clamping unit 40c and the anchor plate 62 in order to maintain the desired joint integrity. Optionally, the anchor plate 62 can also be secured to the paver base 33 with the stake 63.

(24) As shown in FIG. 10, the system of the invention includes a paver edge restraint kit 90 including spools of paver retention strap material 80a for trimming to a desired length for binding paver units in an installed paved surface as a portion of a clamping edge restraint system. The kit 90 further includes a plurality of clamping units 40d each having a rotatable shaft 48 with a slot 48a dimensioned to receive one end of the paver retention strap material and having a lever receipt member. Optionally, the kit 90 may also include clamping lever 55d dimension for engagement with the clamping lever receipt member to cause rotation of the shaft 48 and thereby tightening of a paver retention strap 22d mounted to the shaft 48 to retain the joint integrity of the installed paved surface. Preferably, the clamping units 40d further includes a ratchet wheel 46 having teeth 43 which are engaged by a pawl arm 44 to retain tension in a tightened paver retention strap 22d after installation of the pavers above the paver retention strap 22d. The shaft 48 is preferably rotated by the lever 55d, which detachably mounts through one of a plurality of apertures 45 formed in end of strap retention shaft 48. As shown in FIG. 10, the kit 90 may further optionally include a plurality of anchor plates 62d and spikes 63d for securing the anchor plates 62d to a paver base.

(25) It is intended that the foregoing description is illustrative of the system, methods, and devices in accordance with the present invention and that the present invention be limited only by the appended claims.