The disclosed mulcher has a base unit and a shredding blade in a removable assembly. Two different embodiments are disclosed. In both embodiments, shredded material is removed from air exiting the shredding blade before it reaches an exhaust port. In one embodiment, the material is removed by a filter. In the other embodiment, walls are arranged so that debris must double back against high-speed airflow leaving the shredding blade before exiting the unit. The shredding blade can be mounted in front of and on the same shaft as an air impeller, with the back surface of the shredding blade being supported by the impeller. In another embodiment, the air impeller and the shredding blade are carried in assemblies that are separable from each other and are each separately attachable to a base unit. A detachable power module and a detachable blower are also shown. The power module has a safety switch that disables the power module when it is removed. A power receptacle is shown with a switch that alternately switches power to either the shredder motor or to the power receptacle, but not to both simultaneously.

FIELD OF THE DISCLOSURE

This disclosure generally relates to products used to clean residential yards, and more particularly to products used to collect and dispose of fallen leaves or yard waste.

BACKGROUND OF THE DISCLOSURE

Fallen leaves and yard waste are often collected and bagged or composted. Unless shredded, bagged leaves or yard waste can be bulky. Unfortunately, conventional shredders that are used to shred leaves and yard waster can be large and expensive. The large size can be inconvenient, particularly given that the product is generally used during only one season of the year.

The applicants have developed a mulcher that has a removable shedder assembly that enables the product to be used for shredding leaves, yard waste, or other relatively light-weight materials. The shredder assembly can also be removed, enabling the vacuum to be used as a conventional utility vacuum. Because utility vacuums are used during all seasons, the product has more overall use.

DETAILED DESCRIPTION

One example of a mulcher10that embodies the invention is illustrated in the figures. The illustrated mulcher has three primary parts: a base unit12, a shredder assembly14(seen inFIGS. 1-8), and a basic head unit16(seen inFIGS. 15-21). Each part will be described in turn.

The illustrated base unit12has a tank wall20, a closeable port22, and an open top24(seeFIGS. 8 and 9). The volume within the tank wall20defines a tank chamber (or storage reservoir) that is used to store collected dirt and debris, and can vary in size to meet consumer demands. The port can be used as an inlet during conventional vacuuming, or sealed with a cap (not shown) during mulching. The open top accommodates either the shredder assembly14(during mulching) or the head unit16(during conventional vacuuming).

The base unit12can also include optional features like wheels or casters30, a storage compartment32, or a drain34for a wet/dry vacuum. A handle35can also be attached.

The shredder assembly14(best seen inFIGS. 8-14) has a mulching inlet36, a power module37, and a lower rim38. The mulching inlet can be used to collect leaves or other yard waste. The illustrated mulching inlet is part of a pathway that is relatively straight and has a relatively wide diameter. It has only two turns, each through an angle of less than 45°. Together with the 3½″ diameter of the inlet and its relatively short length (less than 10″), the straightness of this pathway provides a clog-resistant, easy-feeding inlet for leaves or yard waste. Other arrangements are possible, but it is preferred that the pathway to the power module be relatively wide and straight.

The power module37cuts the material that is drawn in through the mulching inlet36. As seen inFIG. 11, the illustrated power module is powered by a motor39, and preferably has a mulcher (or shredding) blade40that is optimized for shredding leaves, rather than for moving air. In the illustrated arrangement, the shredding blade is mounted in front of and on the same shaft41as optional air impeller blades42. In this example, the air impeller blades help to draw material to the shredding blade. InFIG. 12, the illustrated shredding blade is made of metal, and sits on top of and is supported by plastic impeller blades. This arrangement may help to prevent the shredding blade from deforming under centripetal force.

As seen inFIG. 11, the illustrated motor39is mounted between top and bottom covers43aand43bthat fit against a motor plate44. The shaft41extends through the motor plate, and a spacer45on the shaft provides clearance between the impeller blades42and the motor plate. A power switch46on the top cover enables a user to switch the motor on and off.

The power module37fits onto a receptacle48. As best seen inFIG. 8, in this example the receptacle is in the shredder assembly14. Although positioning the receptacle in the shredder assembly is generally preferred, in some instances it might be useful to mount the power module onto a receptacle in the base unit12. Here, mounts49on the motor plate44enable the power module to be screwed onto the shredder assembly for ease of servicing. If the shredding blade40or the motor39would need to be repaired or replaced, the owner could remove the power module and return that assembly alone to the manufacturer or supplier for service.

For safety, special care has been taken to minimize the risk of misuse of the power module37. As seen inFIGS. 11 and 13, a safety switch50is mounted to the illustrated power module. A cooperating blade51(best seen inFIGS. 9 and 10) is mounted to a frame52within the shredder assembly14. Contact between the blade and the safety switch is needed for power to pass through the switch. When the power module is seated onto the receptacle48, the blade contacts the safety switch, allowing power to pass through to the motor39. Removing the power module from the receptacle breaks contact between the blade and the safety switch, disabling the motor. Similarly, if the frame is removed from the bottom of the shredder assembly, the blade loses contact with the safety switch and the power supply is shut off.

As suggested inFIGS. 9 and 10, when the power module37is seated onto the receptacle48, the shredding blade40can spin within a mulcher housing56that is mounted within a cover57of the shredder assembly14. The mulcher housing has a volute or similar arrangement that directs mulched material to a chamber outlet58. Directional walls59are connected to the chamber outlet, and steer mulched debris and air that is ejected from the mulcher housing into a tangential path around an annular skirt wall60of the cover. While proceeding along that path, heavy debris falls into the storage reservoir in the base unit12. A downwardly directed segment61at the end of a deflector62helps assure that lighter debris is also directed to the base unit.

The illustrated shredder assembly14does not require a filter. As can be understood fromFIG. 14, the skirt wall60, a lower wall63on the frame52, a vertical rear wall64on the frame, and an annular inner wall65on the frame form a channel around the exterior of the directional walls59. This channel leads to the sole exhaust port66on the shredder assembly, and forces large particles of debris in the unit to double back against the flow of air exiting the downstream end of the directional walls before they can reach the exhaust port. (As mentioned previously, the port22on the base unit12can be sealed with a cap when the shredder assembly is in use.) It is believed that the high-speed airflow exiting the directional walls will help to knock any large particles from the airflow heading in the opposite direction (toward the exhaust port), helping to reduce or eliminate the need for a separate filter.

In the illustrated device, small holes are shown in the lower wall63. These holes can help reduce pressure within the storage reservoir by permitting some air to exit the device without doubling back against the flow of air from the directional walls59. The small size of the holes prevents large particles from taking this path. A solid wall (with no apertures) can also be used.

The illustrated exhaust port66(FIG. 14) is positioned on the skirt wall60and is covered by an exhaust door67(FIGS. 6 and 10). The exhaust door is hinged at the top so that it swings outwardly when the pressure inside the vacuum exceeds the outside pressure, allowing air to exhaust from the unit. When the unit is turned off, the weight of the door causes it to close.

The lower rim38of the shredder assembly14is arranged so that it can be attached to the open top24of the base unit12. Three latches68are provided on the illustrated base unit, and can be used to hold the shredder assembly to the base unit. Conventional latches are known.

The latches68are arranged so that they can also hold the head unit16to the base unit12. Although other arrangements are possible, providing the expensive parts of the latches on the base unit, rather than on both the shredder assembly14and on the head unit, may be preferred as a way to minimize cost.

When the shredder assembly14is attached to the base unit12, the opening of the lower rim38enables shredded leaves or yard waste cut by the shredding blade40to pass to the storage reservoir in the base unit. When the shredder assembly is removed from the base unit, the open top24of the base unit also accommodates the head unit16.

As seen inFIGS. 15-21, mounting the head unit16on the base unit12creates a unit that can operate as a conventional utility vacuum cleaner. Comparable arrangements are described in U.S. Pat. No. 6,530,116. The disclosure of that patent is incorporated by reference into this disclosure.

In the illustrated device, a shredder power cord (not shown) extends from the shredder assembly14and can be used to provide AC power to the shredder motor. An optional power receptacle69, best seen inFIG. 11, is electrically connected to the shredder power cord through a switch. The switch can be used to switch power coming in through the power cord to either the motor or, alternatively, to the receptacle. Providing a switch that directs power either to the motor or to the receptacle, but not to both simultaneously, helps to reduce the chance of overloading the circuit that the power cord is plugged into.

A detachable blower72can be used with either the shredder assembly14or the head unit16. When used with the head unit, the blower provides the vacuum used for conventional vacuuming, as explained in the U.S. Pat. No. 6,530,116. When used with the shredder assembly, the blower can be used as an accessory tool. In that arrangement, a blower power cord for the blower can be plugged into the receptacle68on the shredder assembly, eliminating the need for the user to extend two separate cords to the primary power outlet. A caddy or supporting frame74on the shredder assembly (FIG. 9) accommodates the blower when it is not in use.

Another example of a shredder vacuum10′ is illustrated inFIGS. 32-40. This shredder vacuum10′ also has three primary parts: a base unit12′, a leaf shredder assembly14′, and a head unit16′. Again, each part will be described in turn.

The illustrated base unit12′ has a tank wall20′ (FIG. 38), a closeable port22′, and an open top24′. The storage reservoir within the tank wall is also used to store collected products, and can vary in size to meet consumer demands. The port can be used as an inlet during conventional vacuuming, or sealed with a cap26′ during mulching. The open top accommodates either the shredder assembly14′ (during mulching) or the head unit16′ (during conventional vacuuming).

The base unit12′ can also include optional features like wheels or casters30′, a storage compartment32′, or a drain34′.

The shredder assembly14′ has a mulching inlet36′, a shredding blade40′ (FIG. 38), and a lower rim38′. The mulching inlet can be attached to a hose and is used to collect leaves. The shredding blade cuts the leaves that are drawn in through the inlet. The shredding blade is powered by a motor, and is preferably optimized for shredding leaves, rather than for moving air. The lower rim is arranged so that it can be attached to the open top24′ of the base unit12′, and has an opening138′ (FIG. 36) that enables the shredded leaves to move through a passage139′ from the shredding blade to the storage reservoir in the base unit.

Unlike in the other embodiments, this shredder assembly14′ also has an upper opening136′. The upper opening accommodates the head unit16′.

The shredder assembly14′ can also house an independent shredder motor for driving the shredding blade40′. A shredder power cord running to the shredder motor can be used to provide AC power. When the shredder assembly is provided with its own power cord, it can also be provided with a power receptacle68′, as seen inFIG. 37. That receptacle is electrically connected to the shredder power cord. Including a receptacle on the shredder assembly can provide the same advantage described above.

The illustrated head unit16′ has a motor, an air impeller, a head inlet140′, and an exhaust port. The air impeller provides the motive force for drawing air, leaves, or other materials through the device. A conventional vacuum motor can be used to power the impeller. Relying on a separate impeller to provide the power for moving air through the device allows the shredding blade40′ to be specifically designed for shredding, rather than for moving air. Thus, a more efficient shredding blade can be used. Similarly, the air impeller can be specifically designed to move air and not for shredding, as is the case in some household leaf vacuums.

The head inlet140′ opens to the storage reservoir in the base unit12′, enabling the impeller to draw a vacuum in the reservoir through a passage144′ from the reservoir to the air impeller. The vacuum pulls leaves through the mulching inlet36′ during mulching operations and pulls dirt or debris through the port22′ in the base unit during vacuuming operations. The exhaust port allows air to escape from the unit.

The head unit16′ can also include one or more filters. The illustrated filter150′ is a common paper filter mounted on a filter cage. The illustrated additional filter152′ is a conical filter that preliminarily filters the air before it reaches the paper filter. A flange154′ (FIG. 36) on the additional filter can be sized so that it can rest on an upper rim on either the open top24′ of the base unit12′ or on an upper opening156′ on the shredder assembly14′.

As seen inFIG. 38, the illustrated head unit16′ includes a supporting frame174′ and a detachable blower72′, which houses the motor and the air impeller. The illustrated blower can be separated from the supporting frame so that the blower can be used separately. Non-detachable motor/impeller assemblies can also be used with the head unit.

An impeller power cord can be used to provide AC power to the motor in the detachable blower72′. When the shredder assembly14′ is provided with a separate shredder power cord and receptacle, the impeller power cord can be plugged into the receptacle on the shredder assembly to prevent the need for two separate cords to extend to user's primary power outlet.

The illustrated embodiments provide differing options for mulching yard waste while being able to use a conventional wet/dry vacuum cleaner tank as the storage reservoir for the mulched material. The embodiment ofFIGS. 1-21utilizes air flow paths generated in the tank to minimize the amount of mulched material that passes out of the tank. The embodiment ofFIGS. 22-38utilizes conventional vacuum cleaner filtering to minimize the escape of mulched material. In each embodiment, much of the mulched material that is entrained in air flowing from the shredding blade is removed from air before the air passes out of the storage reservoir.

This disclosure describes specific applications of the invention, and is intended to be illustrative only. It will be apparent to those of ordinary skill in the art that changes, additions, and deletions may be made to the disclosed embodiments without departing from the spirit and scope of the disclosure. The scope of the invention is set out in the following claims.