Not applicable.
Not applicable.
Field of the Invention
The inventions disclosed and taught herein relate generally to wet/dry vacuum appliances, and more specifically, are related to a bypass vent system for use with wet/dry vacuum appliances.
Description of the Related Art
Vacuum appliances capable of picking up both wet and dry materials, commonly referred to as wet/dry vacuums, are generally well-known. Such vacuums with both wet and dry capabilities are often used in workshops, basements, garages, and other environments where both wet and dry debris can accumulate and needs to be collected for separate disposal.
Wet/dry vacuums conventionally consist of a collection tank or canister, sometimes mounted on wheels or casters, and a cover or lid upon which a motor and impeller assembly is mounted. The motor and impeller assembly creates a suction within the canister, such that debris and liquid are drawn in to the canister through an air inlet to which a flexible hose can be attached. A filter within the canister prevents incoming debris from escaping from the canister while allowing filtered air to escape. One example of such an exemplary wet/dry vacuum is shown in U.S. Pat. No. 4,797,072.
In the usual canister- or tank-type vacuum cleaners that are used for collecting various types of material, they are sometimes used for collecting water or other liquid debris. In a typical vacuum cleaner of this type, the vacuum cleaner motor is supported on a removable lid for the debris collection drum and drives an impeller fan having an inlet side that communicates with the drum interior and draws a vacuum therein, allowing water or liquid debris to be drawn into the collection drum by way of a vacuum hose or the like.
In the usual canister vacuum cleaner, the lid is a generally flat surface disc or plate. To provide the lid with the strength needed for supporting the motor, especially while it is in operation, and for supporting an air filter assembly, the lid is typically formed of a strong, relatively rigid polymer or metal disc having a periphery that is shaped to sealingly engage the upper end of the side wall of the cylindrical tank or drum. A hole is cut through the lid just beneath the mounting for the motor and this hole provides communication between the interior of the tank and the impeller fan driven by the motor.
A filter assembly is interposed between the interior of the tank and the inlet to the impeller fan for capturing particulate matter so that it does not escape into and past the fan and is not expelled from the vacuum cleaner. In the typical tank vacuum cleaner, directly beneath the lid of the tank and at the inlet to the impeller fan, there is a support for a replaceable filter element. Typically, the filter support is in the form of a generally cylindrical cage, and the filter element is in the form of a cylindrical annulus or sleeve of open cell foam material which is removably fitted over the filter cage. The annular sides of the filter cage are defined by vertical ribs, shaped and placed to support the surrounding filter element, yet spaced apart so as not to interfere with air flow. The bottom of the filter cage is closed off.
In situations where liquid or wet materials are being collected, it is necessary that the flow out of the tank and into the vacuum cleaner motor be halted before the liquid or wet material is drawn into the motor. This is typically effected by way of a float element located within a filter cage assembly. The filter cage of the typical canister vacuum cleaner is secured to the underside of the lid around the hole through the lid, and is included for the purpose of supporting a cylindrically-shaped filter element. Typically, the filter cage is a molded plastic unit with an annular collar at its upper edge, and may be of cylindrical, oval, or numerous other shapes, as appropriate. Inside the filter cage, there is a ball or cylinder float element that sits on the base of the filter cage and is adapted to float up within the filter cage once the level of liquid in the tank rises above the bottom of the filter cage. The float element eventually floats high enough to seal the inlet to the impeller fan. Further operation of the vacuum cleaner is blocked until the tank is emptied of collected material. At the same time, the filter element may also be replaced if so desired by the user.
The prior art has described various types of devices that automatically indicate when the debris or liquid level in a vacuum cleaner has reached a critical level, thereby alerting the operator of the problem so that operation of the vacuum may be stopped, and the canister emptied. At that point, continued operation of the vacuum cleaner will result in ineffective or inefficient cleaning, or even worse, it may cause damage to the motor and fan unit. Illustrative patents describing such approaches include U.S. Pat. No. 2,230,113 to Hein; U.S. Pat. No. 2,758,670 to Doughman et al; U.S. Pat. No. 2,764,256 to Allen; U.S. Pat. No. 2,814,358 to Beede et al; U.S. Pat. No. 2,817,414 to Ferraris; U.S. Pat. No. 2,863,524 to Buda; U.S. Pat. No. 3,172,743 to Kowalewski; U.S. Pat. No. 3,626,545 to Sparrow; U.S. Pat. No. 3,870,486 to Eriksson et al; U.S. Pat. No. 4,246,676 to Hallsworth et al; U.S. Pat. No. 4,294,595 to Bowerman; and U.S. Pat. No. 4,623,366 to Berfield et al.
The prior art vacuum cleaner dirt level detection devices can be divided into two general categories. These devices have either floats that are designed to operate in vacuum cleaners which pick up liquids, or they have diaphragm devices that are affected by the difference in pressure between two points in the vacuum cleaner caused by the clogging of a vacuum cleaner dirt collecting bag. When the pressure differential reaches a threshold, the diaphragm triggers a sequence of mechanical or electrical steps which result in either the dust bag cover opening, a light or audible signal warning the operator to shut down the vacuum cleaner, or automatic powering down of the motor fan unit. U.S. Pat. No. 4,623,366 to Berfield is representative of the devices having a float-based system. The float devices rely generally on the principle of buoyancy which causes a float to rise and seal against a seat when a sufficient amount of water has accumulated in the collection container of the vacuum cleaner. The float blocks the fan inlet opening so that even if the motor fan unit continues to run, additional water is not pulled into the system. These float devices are thus not designed to operate by sensing a differential air pressure on opposed sides of a valve.
U.S. Pat. No. 2,817,414 to Ferraris is a typical vacuum cleaner employing a differential pressure diaphragm, or sensor, which acts to detect an increase in pressure between two points in the vacuum cleaner. In the Ferraris device, pressure readings are taken between the inside and the outside of a dust collecting bag. As the bag fills with dirt, a differential force is exerted upon a control diaphragm. At a predetermined threshold, the diaphragm distorts and sets in motion a sequence of pneumatic, mechanical and/or electrical steps which de-energize the motor fan unit. These latter type of control devices, while addressing the issue, are both complicated and expensive to manufacture.
As shown in U.S. Pat. No. 4,185,974, a canister- or tank-type vacuum cleaner which uses a generally cylindrical filter element that is fitted around a generally cylindrical filter cage is described, wherein the cage is an integral plastic molding with the lid that closes the tank of the vacuum cleaner; the vacuum cleaner motor sits atop the lid; the lid is removably sealed to the canister; and, inside the filter cage, there is a freely floating ball, which floats up through the cage as the tank becomes filled to seal the air outlet to the motor. The bottom end of the filter cage is closed off by a bottom cover. An inlet grid element, including a grid covered opening, is disposed across the hole through the tank lid for permitting air to pass through the hole in the lid while also enclosing the top end of the filter cage as a safety feature to block access to the rotating impeller fan. A generally flat wall extends from the grid to the tank lid. The bottom edge of a sleeve extending downward from the grid constitutes a seat against which the float seals upon rising to a predetermined level. If the fan continues to operate after its inlet is blocked by sealing of the float against the seat, the fan motor overheats. This causes the molded plastic grid unit to overheat at a time when there is an upward force transmitted through the float to the sleeve portion of the grid unit. As a result, the grid unit distorts, often resulting in a faulty sealing between the float and seat at the bottom edge of the sleeve.
U.S. Pat. No. 4,623,366 describes a wet/dry canister-type vacuum cleaner that is provided with a plastic grid unit that includes a spherical cup-like main section, an upper annular mounting lip, a short tubular support disposed within the main section with the lower end of the support surrounding a central inlet opening in the latter, and a grid extending across the support at the top thereof and disposed below the mounting lip. The lower end of the support constitutes a seat for a floating ball valve element. An axially extending slot in the support provides a drain for liquid that may be accumulated by the main section at the interior thereof.
The inventions disclosed and taught herein are directed to an improved wet/dry vacuum appliance having a bypass vent system.
Vacuum appliances capable of picking up both wet and dry material are described, the vacuum appliances including an impeller configured to induce liquid into the vacuum appliance, a motor configured to turn the impeller, a restrictor to prevent the liquid from being ingested into the motor impeller, and a bypass vent configured to allow sufficient air to reach the motor impeller chamber in order to keep the motor impeller chamber cool while the restrictor is preventing the liquid from being ingested into the motor impeller. The vacuum appliance may include a drum configured to retain the solid and/or liquid debris and an impeller intake between the impeller and the drum. The restrictor may comprise a float configured to rise with a level of the liquid in the drum and prevent the liquid from entering the impeller intake. The bypass vent may be configured to allow air to bypass the restrictor and/or the drum. The bypass vent may comprise a bypass area of between about 0.01 square inches and about 0.1 square inches. In one non-limiting embodiment, the bypass area is approximately 0.05 square inches.
The following figures form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these figures in combination with the detailed description of specific embodiments presented herein.
While the inventions disclosed herein are susceptible to various modifications and alternative forms, only a few specific embodiments have been shown by way of example in the drawings and are described in detail below. The figures and detailed descriptions of these specific embodiments are not intended to limit the breadth or scope of the inventive concepts or the appended claims in any manner. Rather, the figures and detailed written descriptions are provided to illustrate the inventive concepts to a person of ordinary skill in the art and to enable such person to make and use the inventive concepts.
The Figures described above and the written description of specific structures and functions below are not presented to limit the scope of what Applicants have invented or the scope of the appended claims. Rather, the Figures and written description are provided to teach any person skilled in the art to make and use the inventions for which patent protection is sought. Those skilled in the art will appreciate that not all features of a commercial embodiment of the inventions are described or shown for the sake of clarity and understanding. Persons of skill in this art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present inventions will require numerous implementation-specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation-specific decisions may include, and likely are not limited to, compliance with system-related, business-related, government-related and other constraints, which may vary by specific implementation, location and from time to time. While a developer's efforts might be complex and time-consuming in an absolute sense, such efforts would be, nevertheless, a routine undertaking for those of skill in this art having benefit of this disclosure. It must be understood that the inventions disclosed and taught herein are susceptible to numerous and various modifications and alternative forms. Lastly, the use of a singular term, such as, but not limited to, “a,” is not intended as limiting of the number of items. Also, the use of relational terms, such as, but not limited to, “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and the like are used in the written description for clarity in specific reference to the Figures and are not intended to limit the scope of the invention or the appended claims.
Applicants have created a vacuum appliance capable of picking up both wet and dry material, including an impeller configured to induce liquid into the vacuum appliance, a motor configured to turn the impeller, a restrictor to prevent the liquid from being ingested into the impeller, and a bypass vent configured to allow sufficient air to reach the impeller chamber in order to keep the chamber and motor cool while the restrictor is preventing the liquid from being ingested into the impeller. The vacuum appliance may include a drum configured to retain the liquid and an impeller intake between the impeller and the drum. The restrictor may comprise a float configured to rise with a level of the liquid in the drum and prevent the liquid from entering the impeller intake. The bypass vent may be configured to allow airflow to bypass the restrictor, as appropriate.
Turning now to the figures in detail,
As shown in
In accordance with conventional designs, the air inlet port 108 is defined in a side wall of the collection drum 102 as shown, or alternatively, may be defined in the lid 111 or within a face of powerhead 104. The powerhead assembly 104 houses a motor (M) and an impeller assembly housed within an impeller chamber, and has defined therein an air exhaust or outlet port 108′. The powerhead assembly 104 is operable to create a suction within the collection drum 102, such that during operation debris and/or liquid is drawn into the collection drum 102 through the hose 99, which is attached to the inlet port 108 via a connection member 98.
From
As will be described herein in further detail, an airflow path is defined such that, during typical vacuum operation, air is taken in through air inlet port 108, filtered through filter 116 (and cage 114), and finally expelled through the air outlet port 108′, leaving vacuumed debris contained within collection drum 102, in accordance with the operation of conventional wet/dry vacuums. The air is propelled through this airflow path by way of the motor M and impeller assembly housed within powerhead 104. The impeller assembly comprises a blower wheel 124 attached to motor M by a nut 125 or similar attachment means suitable for threadably connecting the blower wheel to the Motor via motor shaft Ms. As readily evident from
As indicated above, a float 122, which may take many forms such as a ball or a cylinder, is disposed within filter cage 114. Float 122 rises automatically within cage 114 to restrict the flow of air through vacuum 100 when liquid in the drum, 102 reaches a predetermined level. A plurality of fins (not shown) may optionally be formed within cage 114 to serve as guides to keep the float 122 centrally disposed within cage itself.
In the presently disclosed embodiment of the invention, lower motor frame 136 fits into the bottom face of lid 111, creating an annular seal designated with reference numerals 138. The assembly consisting of motor M, lid 111, and motor frames 134 and 136 may be attached to bottom face 132 of powerhead 104 with screws 140. An impeller intake aperture 142 defined by powerhead bottom 132 provides a path for the flow of air to impeller 128 to be expelled through output port 130. To form a seal between collector member 133 and powerhead bottom 132, an annular ring seal 144 is formed in bottom 132, which interlocks with a corresponding annular groove in collector member 133, in a tongue-and-groove fashion.
As discussed above, during typical vacuum operation, float 122 rises automatically within cage 114 to restrict the flow of air through vacuum 100 when liquid in collection drum 102 reaches a predetermined level. In its raised position, the float 122 may partially seal the intake aperture 142 in the powerhead bottom 132. In this manner, the float 122 acts as a restrictor, preventing liquid from being sucked, or ingested, into the impeller 124, and/or the impeller chamber 131. One can appreciate that the float 122 may take forms other than cylindrical.
In further accordance with the present disclosure, when the airflow path is blocked or otherwise limited, less airflow is available to cool the impeller 124, impeller chamber 131, and motor (M). Additionally, when the airflow path is blocked or otherwise limited, significant suction may be created within the vacuum 100. To alleviate one or both issues, as well as other potential issues, the present invention preferably includes a bypass vent 200 somewhere along the airflow path before, or upstream of, the impeller 124 to allow sufficient airflow to cool the motor M, impeller 124, and impeller chamber 131 even when liquid in drum 102 reaches the predetermined level.
The bypass vent 200 of the present invention provides a small, controlled amount of fresh ambient air, or bypass air, to enter the impeller chamber 131 to keep it cool. At the same time, the bypass vent 200 of the present invention keeps the airflow to a minimum in order to keep the vacuum pressure generated inside the drum 102 to a level that will not pull liquid into the vacuum drum 102 when picking up mixtures of air and liquid.
The bypass vent is preferably tuned and located to allow enough cooling air to keep the impeller chamber 131 and motor M cool while, at the same time, prevent intake of liquid. The reduced vacuum pressure, with the float in the sealed position, must be less than that needed to lift the water from the source up to the intake of the vacuum, which typically would be greater than 10 inches of water head. In one embodiment, with a blocked suction pressure of approximately 40-55 inches of water (1.4-2.0 pounds per square inch, psi), the bypass vent 200 preferably provides a bypass area of about 0.05 square inches located at the interface between the float 122 and the impeller's air intake 142. In one embodiment, referring to
It should be understood that different opening sizes for other peak vacuum pressures would be required. For example, in alternative embodiments, the bypass area may be about 0.01 square inches, about 0.025 square inches, about 0.075 square inches, or about 0.1 square inches. Due to manufacturing tolerances, as well as other considerations, the bypass area may be between about 0.01 square inches and about 0.025 square inches, between about 0.025 square inches and about 0.05 square inches, between about 0.03 square inches and about 0.07 square inches, between about 0.05 square inches and about 0.075 square inches, or between about 0.07 square inches and about 0.1 square inches.
Furthermore, as will be discussed in greater detail below, the bypass vent 200 may be located in other places, such as a hole near the top of the vacuum 100. Additionally, in alternative embodiments, the notches are provided in the drum 102, the float 122, the impeller intake 142, and in an insert or grille between the impeller 124 and the drum 102.
In accordance with one embodiment of the present disclosure, the bypass vent 200 is significantly smaller than the main hose air input port, or inlet, 108. More specifically, the bypass vent 200 is preferably tuned to allow a consistent amount of air to bypass the seal between the float 122 and the intake aperture 142. This bypass, or leakage, air keeps the air temperature inside the impeller chamber 131 well below the maximum operating temperature of the motor M and other vacuum components, such as the motor's lower frame. At the same time, this bypass air is small enough that the vacuum pressure generated inside the drum 102 is low and will no longer pick up liquid, thus keeping liquid from ever entering the impeller chamber 131. Thus, by hitting this critical region, the bypass vent 200 allows the vacuum 100 to run long term with the float 122 in the raised position without overheating the motor M and without allowing further liquid to be pulled into the vacuum 100.
Thus, the bypass vent 200 provides a controlled area of air leakage into the impeller chamber 131 to introduce fresh cooling air while, at the same time, choking off or substantially reducing the airflow to a flow rate sufficient to minimize the vacuum pressure developed inside the drum 102, and thus stop the inflow of liquid into the drum 102 for air/liquid mixtures. This controlled air leakage, or bypass air, can be provided at the interface between the float 122 and the impeller inlet 142, on the inlet 142 itself, or in the float 122 itself, or a combination thereof. As discussed above, the bypass vent 200 may be specific holes, notches, or slits in either the float 122 or the rim of the impeller intake 142. For example, three or more short ribs, approximately 0.010″ or smaller, may be raised on the top of the float 122, or some other standoff feature may be built in to the top of the float 122. Alternatively, as shown in
In still another embodiment of the present disclosure, and referring to the perspective view of float 122 shown in
Alternatively, referring to
Referring now to
Other and further embodiments utilizing one or more aspects of the inventions described above can be devised without departing from the spirit of Applicant's invention. In one embodiment, the bypass vent 200 provides airflow directly from the outside of the vacuum 100. For example, a tube may be used to connect the intake port 142 of the impeller chamber 131 to the outside of the vacuum 100. Thus, the bypass vent 200 may allow the impeller to induce airflow to bypass the float 122, the drum 102, and/or the impeller intake 142. In alternative embodiments, the bypass vent 200 may comprise one notch, three notches, four notches, and/or five or more notches. Further, the various methods and embodiments of the present invention can be included in combination with each other to produce variations of the disclosed methods and embodiments. Discussion of singular elements can include plural elements and vice-versa.
The order of steps can occur in a variety of sequences unless otherwise specifically limited. The various steps described herein can be combined with other steps, interlineated with the stated steps, and/or split into multiple steps. Similarly, elements have been described functionally and can be embodied as separate components or can be combined into components having multiple functions.
The inventions have been described in the context of preferred and other embodiments and not every embodiment of the invention has been described. Obvious modifications and alterations to the described embodiments are available to those of ordinary skill in the art. The disclosed and undisclosed embodiments are not intended to limit or restrict the scope or applicability of the invention conceived of by the Applicants, but rather, in conformity with the patent laws, Applicants intend to fully protect all such modifications and improvements that come within the scope or range of equivalent of the following claims.
The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/142,138, filed Dec. 31, 2008, and U.S. patent application Ser. No. 12/651,243, filed Dec. 31, 2009, the contents of all of which are incorporated herein by specific reference in their entirety.
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Number | Date | Country | |
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20140182078 A1 | Jul 2014 | US |
Number | Date | Country | |
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61142138 | Dec 2008 | US |
Number | Date | Country | |
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Parent | 12651243 | Dec 2009 | US |
Child | 14196103 | US |