The present disclosure relates generally to the field of manhole and hatch cover assemblies.
A manhole provides access to an underground passage or confined area. The underground passage or confined area may contain public utility equipment, such as sewer lines, storm drains, electrical and telecommunication cables, etc. A manhole or hatch cover is a removable plate that forms a lid over the opening of a manhole. Manhole covers are used to prevent individuals and objects from falling into the manhole, as well as to prevent unauthorized access into the manhole. The terms “manhole cover” as used herein to mean either a manhole cover, or a hatch cover, and the like.
Manhole covers are conventionally formed of cast iron, which makes them inexpensive, strong, and heavy, usually weighing more than 100 pounds. The weight helps to keep them in place when traffic passes over them, and makes it difficult for unauthorized individuals to remove them. In addition to being constructed of cast iron, manhole covers may also be constructed of concrete, glass-reinforced plastic or other composite materials, and other materials, or any combination thereof
Despite their significant weight, manhole covers can be dislodged in several ways. For example, an explosion within a manhole can cause a sudden pressure buildup that can dislodge the manhole cover. For example, gases (e.g., methane from sewage or natural gas from a leaking natural gas line) can become trapped in the space within the manhole, as well as within the passages or spaces connected to the manhole. The gas may be ignited, for example, due to a spark from a frayed power cable. Some explosions generate sufficient pressure to dislodge the manhole from its frame. However, higher-intensity explosions may propel the manhole cover up to 20 feet or more into the air. A heavy manhole cover flying through the air can be extremely dangerous or deadly. In addition to the human and property damage risk, individuals or objects may subsequently fall into the now-uncovered manhole.
Excessive rainfall and flooding can also dislodge manhole covers. For example, storm drain systems may become overfilled during periods of excessive rainfall. Water may flow through the storm drain systems and up through a manhole. Sufficient pressure from the water may dislodge manhole covers and “float” them away. The now-uncovered manhole can be obscured by dirty water, thereby providing a dangerous risk that an unwary victim may inadvertently fall into the manhole and into the storm drain system.
Various embodiments relate to manhole cover assemblies. An example manhole cover assembly includes a manhole cover and a latch assembly. The manhole cover is supportable by a seat of a manhole frame. The latch assembly includes a latch housing fixedly coupled to the manhole cover. A latch plunger is slidably coupled to the latch housing. The latch plunger includes a follower arm. A latch lever is rotatably coupled to the latch housing. The latch lever includes a stop. The latch lever is rotatable relative to the latch housing between a locked position and an unlocked position. The stop is structured to engage the manhole frame when the latch lever is rotated to unlocked position so as to force the manhole cover away from the frame.
These and other features, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described below.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the disclosure will become apparent from the description, the drawings, and the claims.
It will be recognized that some or all of the figures are schematic representations for purposes of illustration. The figures are provided for the purpose of illustrating one or more implementations with the explicit understanding that they will not be used to limit the scope or the meaning of the claims.
Various events, such as explosions or flooding, can cause a sudden pressure increase beneath a manhole cover, which can force the manhole cover from its frame. Several manhole cover assemblies have been developed to release pressure buildup from beneath a manhole cover while limiting displacement of the manhole cover relative to its frame. For example, some manhole cover assemblies include legs or other features to permit limited displacement of the manhole cover. During a pressure-inducing event, the legs contact a bottom surface of the frame, thereby limiting travel of the manhole cover. However, the kinetic energy of the rising manhole cover is concentrated into relatively small areas of the frame surface that are contacted by the legs. Accordingly, significant pressure-inducing events, such as explosions or floods, may damage the frame. This is undesirable because the frame is typically cemented or otherwise permanently fixed in a street or roadway, and removal and replacement of the frame is a significant and costly undertaking.
A frame 118 is configured to support the manhole cover 102 over the opening of a manhole (not shown). The frame 118 is fixedly secured (e.g., cemented or otherwise fixed) within a substrate (e.g., street, road, sidewalk, etc.) defining the opening of the manhole (not shown). The frame 118 is generally ring-shaped, having a peripheral wall 120 extending between an upper surface 122 and an opposite lower surface 124. The peripheral wall 120 has an inner diameter that is slightly larger than an outer diameter of the manhole cover 102. In operation, the upper surface 122 of the frame 118 is generally flush with the road or other surface that defines the manhole.
The frame 118 also includes a projection 126 that extends radially inward from the peripheral wall 120. The projection 126 defines a seat 127 facing longitudinally outward toward the upper surface 122, and defines a catch 129 facing longitudinally inward toward the lower surface 124. The seat 127 is structured to support the manhole cover 102 within the frame 118. More specifically, the bottom surface 110 of the manhole cover 102 proximate the outer periphery 112 rests on, and is supported by, the seat 127 when the manhole cover is in a seated position. The top surface 108 of the manhole cover 102 is generally flush with the upper surface 122 of the frame 118 when the manhole cover 102 is in the seated position. The catch 129 is structured to be engaged by the each of the latch 114 and the lug 116 during a pressure-inducing event so as to retain the manhole cover 102, while controllably dissipating pressure from within the manhole.
The latch and lug assemblies 104, 106 are also configured to controllably dissipate pressure from within the manhole during a pressure-inducing event. As discussed in further detail below, the latch and lug assemblies 104, 106 permit the energy from a pressure-inducing event (e.g., an explosion or flood) to move the manhole cover 102 from the seated position to the unseated position. When in the unseated position, high-pressure fluid (e.g., air or water) and debris may escape from the manhole through the space then available between the manhole cover 102 and the frame 118, proximate the outer periphery 112 of the manhole cover 102 and the projection 126 of the frame 118. Thus, in response to a pressure-inducing event, the latch and lug assemblies 104, 106 of the manhole cover assembly 100 operate to controllably release pressure from within a manhole rather than allowing the pressure to build up beneath the manhole cover 102 to a potentially dangerous level. In doing so, the latch and lug assemblies 104, 106 prevent the manhole cover 102 from being launched from the frame 118 by a pressure-inducing event, while also preventing damage to the frame 118 and the surface (e.g., street) to which the frame is secured.
The manhole cover assembly 100 also includes extractor rails 113 fixedly coupled (e.g., welded) to each of the manhole cover 102 and the lug assembly 106 so as to form a gradual ramp from the lug 116 to the bottom surface 110 of the manhole cover 102. The extractor rails 113 facilitate easy removal of the manhole cover 102 from the frame 118. In particular, as the manhole cover 102 is pulled away from the frame 118, extractor rails 113 slide against the upper surface 122 of the peripheral wall 120 of the frame 118. Upon the manhole cover 102 being completely removed from the frame 118, a skid pad 115 affixed (e.g., bolted) to a bottom surface 111 of the lug assembly 106 contacts the outer surface (e.g., roadway). The skid pad 115 may be formed of high molecular weight polyethylene (HMWP), Teflon, rubber, or other materials.
As illustrated in
In one embodiment, as shown in
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The latch lever 132 also defines a stop 200 that extends from the first end 180 of the latch lever member 176. The stop 200 includes an outer extraction surface 202. As discussed further in connection with
The latch lever member 176 defines a first bore 204 extending through the latch lever member 176 along a first bore axis 206, from the top surface 145 to the bottom surface 147. The first bore axis 206 is positioned at an angle α relative to the longitudinal axis 178 of the latch lever member 176. In one embodiment, α is 30 degrees. In another embodiment, α is 45 degrees. In various other embodiments, α is any of less than 30 degrees, between 30 and 45 degrees, and between 45 and 90 degrees. As discussed further in connection with
The latch lever 132 also defines a second bore 208 extending through the latch lever member 176 proximate the second end 182 along an axis perpendicular to the longitudinal axis 178. As shown in
Turning back to
As discussed briefly in connection with
Further rotation of the latch lever 132, while pivoting on the latch bolt 133 results in two actions. First, the actuating arm 188 presses against the follower arm 174, thereby sliding the latch plunger 130 so as to compress the latch spring 210 and move the latch 114 away from the frame 118 and into the latch housing 128. Second, rotation of the latch lever 132 causes the outer extraction surface 202 of the stop 200 to contact the seat 127 and the inner surface of the peripheral wall 120 of the frame 118. As the latch lever 132 is rotated, the contact between the stop 200 and the frame 118 forces the latch bolt 133 upwards and radially outwards against the slot-shaped opening 142. Accordingly, the force exerted on the slot-shaped opening 142 of the latch housing 128 causes the manhole cover 102 to move upward and radially outward from the frame 118. The lever arm created by the latch lever 132 further operates to amplify the input force imparted on the latch lever 132 to produce an even greater output force against the latch housing 128. Thus, the latch assembly 104 facilitates easy removal of the manhole cover 102 from the frame 118 such that a single individual can remove the manhole cover 102 himself or herself.
As the manhole cover 102 is pulled away from the frame 118, the extractor rails 113 (
While this specification contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular implementations. Certain features described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
As utilized herein, the term “substantially” and any similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided unless otherwise noted. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims. Additionally, it is noted that limitations in the claims should not be interpreted as constituting “means plus function” limitations under the United States patent laws in the event that the term “means” is not used therein.
The terms “coupled” and the like as used herein mean the joining of two components directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two components or the two components and any additional intermediate components being integrally formed as a single unitary body with one another or with the two components or the two components and any additional intermediate components being attached to one another.
It is important to note that the construction and arrangement of the system shown in the various example implementations is illustrative only and not restrictive in character. All changes and modifications that come within the spirit and/or scope of the described implementations are desired to be protected. It should be understood that some features may not be necessary and implementations lacking the various features may be contemplated as within the scope of the application, the scope being defined by the claims that follow. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.
The present application claims the benefit of priority to U.S. Provisional Patent Application No. 62/219,871, filed Sep. 17, 2015 and the contents of which are incorporated herein by reference in its entirety
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Number | Date | Country | |
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20170081821 A1 | Mar 2017 | US |
Number | Date | Country | |
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62219871 | Sep 2015 | US |