Latch for leaching chamber

Abstract

Two identical arch shape cross section chambers are joined together so that a dome shape part of one end of the chamber is overlapped by the opposing plain end of the second chamber. Thus, one chamber may pivot in the horizontal plane, for adjustment during installation. A latch at the top of the joint between the chamber pair inhibits vertical motion and separation of the overlapping chamber, while permitting horizontal plane pivoting. A latch comprises a tang which cantilevers outwardly from the top of the dome end, to engage a catch which is a flared portion of lip on the overlapping plain end.

Description

TECHNICAL FIELD

The present invention relates to arch shape cross section plastic chambers, which when buried are used for receiving and dispersing wastewater or stormwater.

BACKGROUND

Arch shape cross section plastic chambers have been widely used for receiving and dispersing waters when buried in soil or other media. Examples of such chambers are shown in U.S. Pat. Nos. 4,759,661 and 5,511,903 to Nichols. Typically, chambers are about 4-8 feet in length. They have mating opposing ends, so that like chambers may be connected end to end at joints where there is overlap of one chamber by the adjacent chamber. The joint fit is sufficient to prevent entry of soil and other media. Preferably, the chambers latch together in some positive way, so the overlap fit is not lost, by vertical motion of one chamber relative to the other. See U.S. Pat. No. 5,336,017 to Nichols for an example of chamber joints.

However, sometimes the nature of the terrain for a desired installation requires that chambers be installed non-straight rows. In such situations, a bend in a string of chambers can be accomplished by use of chambers or adapters which have angled ends. See U.S. Pat. No. 5,588,778 to Nichols et al. and U.S. Pat. No. 5,669,733 to Daly et al. More preferably, chambers may be constructed with ends that enable the installer to make one chamber overlay the next, with the long axes running at chosen angle, within some range, for example plus or minus 10 degrees. Sometimes, such types of chambers are referred to as swivel-end chambers. Examples of such chambers, which are sometimes referred to as swivel-end chambers, are shown in U.S. Pat. No. 6,592,293 to Hedstrom et al., U.S. Pat. No. 6,375,388 to Zoeller et al., and U.S. patent application Ser. No. 10/442,810 of Burnes et al.

However, one of the problems attending the previously known so-called swivel end chambers is that there can be a tendency for one chamber to lift off from the other, before the chamber string is backfilled. That can undesirably allow media to enter the chamber string through the resultant gap, which can lead to problems with ingress of material over time during use. Such an adverse condition may be avoided by careful installation, or by the use of mechanical screw fasteners of the like, to attach one chamber to the other once the chambers are laid in place at the desired angle. However, installers may often not take adequate care. They may be annoyed by the nuisance and increased labor which attend the use of mechanical fasteners. Fasteners may not be timely installed, before material gets into the joint. Slight adjustment after fastening is not possible unless the fasteners are removed. Thus there is need for improvements in chambers to overcome the nuisance problem.

SUMMARY

An object of the invention is to provide means for preventing relative vertical motion at the joint between swivel-end chambers. In achieving such object, one or more other objects should be attained. The means has to accommodate any of the different angles of connection which may be possible and desired, allow the use of end caps, be suited for economic manufacturing, be durable during handling, and be easy to install in the field.

In accord with the invention the two like arch shape cross section chambers are joined together so that one chamber may pivot in the horizontal plane, for adjustment during installation, and a latch inhibits vertical motion, or separation, of the chambers. Each chamber has a dome end which can be over-lapped by the opposing plain end, so like chambers may mate to form a joint. The latch is at the top of the chamber, to prevent upward motion of the overlapping chamber while permitting horizontal plane rotation which adjusts the angle between two chambers Preferably, the latch comprises a tang which cantilevers outwardly from the top of the dome end, so a portion of the plain end of the overlapping chamber underlies it, to form a catch portion of the latch. In one embodiment, the catch is a portion of a lip which runs along the arch shape curve plain end of the chamber; more preferably, the catch is an outwardly flared portion of the lip, having in the horizontal plane an arc curve with a radius running from the point of pivoting. Preferably, the two mated chambers are engaged with a pin connection which comprises mating male and female parts of molded plastic chambers.

The invention inhibits inadvertent vertical motion of the overlapping chamber by the installer, prior to backfilling the trench with soil or other media. The good fit of the joint is maintained. The invention is simple and economic to manufacture.

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows is an isometric view of a leaching chamber, with a portion of a like chamber shown in phantom.

FIG. 2 is a vertical lengthwise center plane cross section through the joint of two chambers.

FIG. 3 is an isometric fragment, showing details of the joint between two chambers and how they are latched together.

FIG. 4 is a vertical down view of a fragment of the end of the chamber which comprises female pin and the catch, which is one part of the latch.

FIG. 5 is a cross section view of the structure shown in FIG. 4.

FIG. 6 is a cross section showing an alternate embodiment latch.

FIG. 7 is a top view of the alternate embodiment latch of FIG. 6.

FIG. 8 is a view of the same kind as FIG. 3, showing how an end cap engages the pawl part of the latch.

FIG. 9 is a view like FIG. 2, showing how an end cap is overlapped by the plain end of a chamber.

DESCRIPTION

The present invention, which is described in provisional patent application Ser. No. 60/523,553 filed Nov. 20, 2003, is particularly to useful with the leaching chambers described in pending U.S. patent application Ser. No. 10/677,938 to Brochu et al. and pending U.S. application Ser. No. 10/442,810 of Burnes et al., both filed Oct. 1, 2003. The drawings and text of both applications are hereby incorporated by reference. A preferred embodiment of the patent-pending leaching chambers is sold commercially as Quick4™ Chamber by Infiltrator Systems Inc., Old Saybrook, Conn. 06475, U.S. An example of the invention is described below in terms of such Quick4 chamber. The exemplary chamber of the present invention may be made of injection molded high density polyethylene or polypropylene thermoplastic materials or substitutional materials, using well known techniques of the prior art. See U.S. Pat. No. 5,401,459 to Nichols et al. Some less preferred embodiments of the invention may be made by other plastic forming methods and or of other materials.

In FIG. 1 chamber 20 is shown joined to a like chamber 20A, shown in phantom. It has the features of the aforementioned Brochu et al. chamber. FIG. 2 is a vertical centerline cross section through the joint between the two chambers 20, 20A. (In FIG. 2, chamber 20A is no longer shown in phantom, and it is on the left, compared to being on the right in FIG. 1.) Chamber 20 has an arch shape cross section and corrugations comprised of alternating peaks 24 and valleys 22. The chamber is about 48 inches long, about 30 inches wide, and about 12 inches high. The opposing sidewalls 44 have a multiplicity of slots for leaching of water into the soil.

The two chambers 20, 20A typically will be part of a larger string of chambers which are typically, but not necessarily, identical to chamber 20. The first end 74 of typical first chamber 20 overlaps the opposing second end 76 of a like chamber, e.g., chamber 20A. Second end 76 has a surface of revolution portion 77, called a dome (segment) hereafter. The first end does not have an interior surface of revolution, and thus is referred to here as the plain end, in distinction to the dome end. The design is such that the arch shape interior of the plain end fits the dome. In other chamber embodiments, the plain end may have an interior surface of revolution or other special contour features. The dome 77 enables pivoting of one chamber relative to another about a vertical axis which runs through pin connection 82, 84, typically within plus or minus 10-15 degrees. The overlapping end 74 has a hollow molded female-function pin 84, the interior of which fits over a smaller like male-function pin 82 at the overlapped end 76. The exterior of dome 77 fit with the interior features of the end 74 of the overlapping chamber is sufficiently tight to prevent adverse ingress of surrounding soil and the like, when the chambers are backfilled and used, regardless of the horizontal plane angle between the chambers.

FIG. 3 is a fragmentary view, looking onto the overlap joint between the two chambers 20, 20A. With reference to all FIG. 1-3, a latch 40 at the top of the chamber is comprised of two parts: pawl 25 on the overlapped end 76 of the chamber, and catch 23 on the overlapping end 76 of chamber 20A. Catch 23 is an outwardly flared portion of lip 27, at the top of the chamber end 74, which lip 27 runs along the arch shape opening at the end of the chamber, to enhance rigidity of the end. With reference to FIG. 4, which is a view looking down on end 74, and to related FIG. 5, in the horizontal plane catch 23 preferably has an arc shape of radius R, which runs from pin 84, or the axis of rotation of the end, in absence of a pin. See FIG. 5 with respect to how catch 23 gracefully transitions to the lip 27. In the generality of the invention, catch 23 may be an isolated portion at the peak of the chamber end, and there may be no lip 27 running along the end; and the edge of the local portion of the end which functions as the catch may have a radius R, as described, so there is essential constancy of distance between the latch and pawl within the design angle of rotation.

When two chambers are mated, as shown, tang 29 of pawl 25 overlaps catch 23, to thereby form latch 24, and to thereby inhibit vertical separation of the chambers at the pivotable joint. The nature of the latch permits horizontal plane pivotable adjustment of the overlapping chamber, which is convenient for having chambers run just where desired, within trenches.

With reference again to FIG. 1-3, pawl 25 has a cantilever tang 29, projecting horizontally from pawl body 31. Preferred pawl body 31 has triangular sides and a U-shape cross section in the horizontal plane. The vertical side of the body, that is the edges of the U-opening which faces the joint and mating chamber, inclines away from such, to accommodate the outward flare or tilt of catch 23, as shown in FIG. 4-5. The pawl and catch configurations shown are suitably strong, and may be formed without additional slides or complication, in an injection core and cavity mold which is adapted to make the essential chamber.

When the chambers are connected to make a pivotable joint connection, as described, longitudinal motion of overlapping chamber 74 to and away from the pawl 25 is prevented by engagement of pins 82, 84. When chambers are so-engaged, chamber 20A can be rotated about the pin connection relative to chamber 20B, since catch 23 slides under tang 29, and owing to the arc curve of the catch, the catch and pawl parts stay in approximately the same proximity. Mold design considerations lead to an opening 77 beneath the pawl at the top of the dome end. See FIG. 2; also FIG. 6 discussed below. The details of the plain end, in particular the flared lip portion which comprises the preferred catch, blocks entry of soil in vicinity of the latch. The latch design does not create difficulty in joining two chambers. To make a joint, a first chamber is laid on the ground. Then a second chamber is tilted upwardly and its lower end 74 is overlapped on the dome end of the first chamber, and slipped under the tang of the pawl of the first chamber. The second chamber is then rotated downwardly toward horizontal. Given the placement and conical taper shape of pins 82, 84, the male pin slips within the cavity of the female pin. And, as shown in FIG. 2, the female pin 84 is preferably positioned on the chamber so its lower edge intersects the web of adjacent peak corrugation. Thus, the lower side of the cone of the pin, which faces the interior of the chamber, is missing. While the configuration does not adversely affect pin function, in preventing chamber separation, the omitted cone portion facilities entry of the female pin into the male pin when the chambers are joined as described. Other configurations of pinning can be used, including a pin which is a separate element inserted into holes in the mated chambers.

Preferably, the tip of tang 29 has a slight down-slope, about equal to the tang thickness. See FIG. 3. Such outer tip downward incline is not necessary for the primary function of preventing vertical disengagement. But the tip incline can provide some resistance to chamber longitudinal disengagement, which is additive and little needed when there is pinning as shown in this embodiment. Analogously, motion of the overlapping chamber toward the pawl body will be limited by contact of the lip or chamber end with the body, in the absence of pinning. The body 31 of the pawl may have other shapes than shown. For instance, less preferably, the body may comprise bent up tab 3 IA, as shown in FIG. 6. (Numbers with suffices denote elements which correspond with prior elements.) Reinforcing ribs may be added to tab 31A. As may be implied from the foregoing, in the generality of the invention there may be no pin connections. Other means, or less preferably no means, to prevent lateral disengagement may be used. An example of one other non-pin means is shown in FIG. 7 of aforementioned application Ser. No. 10/442,810.

An end cap, for closing the dome end of a chamber by overlapping the dome end, may have a pin connection as described, to prevent horizontal plane separation. An end cap suitable for the exemplary chamber is described in U.S. patent application Ser. No. 10/677,771 of Burnes et al. The end cap may be used to under the lap plain end of an exemplary chamber, or overlap the dome end. FIG. 8, which is analogous to FIG. 3 and shows the flange 46 of end cap 40 overlapping dome end 76 of chamber 20A. The end cap has a U-shape slot 42, the axial length of which is somewhat longer than the lengthwise dimension of the pawl. The peninsular shape portion within the U is tongue 44. To engage the end cap with the dome end, the end cap is canted so the flange 46 contacts the top of the dome. As the cap is rotated downwardly, the pawl passes through the bottom part of the U. The cap is then slid toward the chamber so tongue 44 fits within the opening 77 (shown in FIGS. 2 and 6) which lies beneath the tang 29 and body 31, to block entry of soil. The top a cap, in place, is shown in FIG. 8. In a variation, the bottom of the U is narrower, and the tongue bends elastically upward, to then spring back into its final place, as the cap is installed. Molded female pin 84C receives the pin 82 of the chamber. If there were no pins, the cap would be held in length-wise place by contact of the edge of the U-bottom of slot 42 with the back side of the pawl. It is desirable to have only one end cap, which can seal either end. When the U-shape slot is the means for cap-to-chamber engagement this goal is achieved. The flange of the end cap is able to slip under the plain end of the chamber, as illustrated in the vertical cross section of FIG. 9. If it is acceptable to have two different end cap configurations in the product line, an end cap for the dome end could alternatively have some or all of the same features of the plain end of the chamber 20.

The cross section view of FIG. 6 and the top view of FIG. 7 show another embodiment of chamber with latch. The outer lip 27A of the end 74A of the chamber does not have the arc shape region which characterizes catch 23, described above. The portion 23A at un-flared lip at the top of the chamber functions as catch. In the FIG. 6-7 embodiment, when the chamber having end 74A is rotated relative to chamber 20B, as illustrated by the arrows and phantom view of lip 27A in FIG. 6, the chamber end and associated lip move to an angled position under the tang 29A, which has a length or projection sufficient for the purpose. Thus, there is change in the relative proximity of the catch and pawl when the overlapping chamber is pivoted, compared to the preferred embodiment of FIG. 1-5. In a further variation, lip 27A may be omitted, and the local portion of the plain ordinary end of the chamber top will function as catch.

While the invention has been described in terms of the Quick4 leaching chamber, it will be useful with other configurations of molded plastic chambers used for leaching wastewater, including those described in the Background, with chambers which are not corrugated, and with chambers used for other purposes, including receiving stormwater. The term dome end should be construed loosely and shall comprehend the end of any chamber which has portions which are shaped to receive and allow pivotable rotational adjustment of an overlapping chamber end, while forming a joint which provide a barrier to entry of surrounding soil or media. In the embodiments described above, the ends of the chambers which mate to form the joint and which have the latch parts may be characterized as valleys, being smaller than the adjacent peaks. It will be appreciated that other embodiments, the invention may be applied to chambers which have overlapping ends which are peaks, i.e., ends which are larger than the adjacent (valley) corrugations.

Although this invention has been shown and described with respect to a preferred embodiment, it will be understood by those skilled in this art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed invention.

Claims

1. In an arch shape cross section chamber, used for receiving and dispersing water beneath the surface of the earth, wherein the chamber has a first dome shaped end and an opposing second end, wherein the ends are shaped so that the second end of a like chamber may overlap said first end and thereby form a horizontally pivotable joint between the chambers, the improvement which comprises: a pawl on the first end and a catch on the second end, to form a latch at the top of joint between two chambers, for inhibiting vertical motion of the overlapped chamber end while permitting horizontal pivotable motion thereof.

2. The improved chamber of claim 1 wherein the pawl comprises a tang, attached to said first end, the so that when two like chambers are connected with said pivotable joint therebetween, the second end of a second chamber underlies the tang.

3. The chamber of claim 2 wherein the pawl further comprises a body projecting upwardly from the top of the first end, and wherein the tang cantilevers from the body.

4. The chamber of claim 2 wherein the second end of the chamber has a lip running along the arch shape opening of the second end.

5. The chamber of claim 4 wherein the lip at the top of the chamber has a flared portion, so that when two like chambers are connected with said pivotable joint, and the second chamber is pivoted, the spacing between the second chamber lip and the first chamber pawl is approximately maintained.

6. The chamber of claim 2 wherein there is an opening in the top of the dome end, in vicinity of the pawl, wherein the catch of the second end covers said opening, to prevent entry of soil, at any angle of pivotable motion between the chambers.

7. The chamber of claim 1 wherein the first end and second end have pin connection points, about which two mated chambers may pivot when joined together.

8. The chamber of claim 5 which further comprises pinning points at the first end and second end of the chamber wherein when two like chambers are connected, pivotable rotation takes place about said pinning points; and, wherein said flared lip portion has an arc shape radius in the horizontal plane.

9. The chamber of claim 7 wherein the chamber first end has male pin and the second end has a female pin which is shaped to receive the male pin of a like chamber.

10. The chamber of claim 8 wherein the chamber first end has male pin and the second end has a female pin which is shaped to receive the male pin of a like chamber.

11. An assembly comprising: a pair of substantially identical first and second arch shape cross section chambers for burial within soil or other media, mated together at a joint which is pivotable in the horizontal plane; each chamber having a dome end and an opposing plain end, wherein said joint is formed by overlapping the plain end of the second chamber onto the dome end of the first chamber; and each chamber having means for pin connection to another chamber; wherein the chambers are pinned each to the other and pivotable about said pin connection; and, a latch which inhibits vertical motion of the plain end relative to the dome end, comprised of. a pawl at the top of the dome end of the first chamber in combination with a catch which is a portion of the plain end of the second chamber; wherein the pawl has a cantilevered tang which projects along the chamber length and overlies said catch portion of the second chamber.

12. The chamber assembly of claim 11, wherein the second plain end of the chamber has a lip running along the arch shape opening of the first end; wherein said catch comprises a portion of said lip which underlies said tang.

13. The chamber assembly of claim 12, wherein said portion of the lip has an arc curve in the horizontal plane, with a radius running from the location of pin connection on the second chamber.