FIELD OF THE INVENTIONThe present invention relates to features for use with vacuum cleaners having a dirt cup. More specifically, the present invention relates to a latch mechanism for release of a bottom lid of a dirt cup to allow access to or emptying of the dirt cup.
BACKGROUND OF THE INVENTIONIt is well known that some vacuum cleaner types, such as upright and canister type vacuum cleaners, use a dirt cup for collection of dirt and debris. The dirt cup typically is removably mounted to the housing of the vacuum cleaner to allow a user to easily remove the dirt cup to empty the contents thereof or to change an internally mounted filter in the dirt cup. It is also well known that dirt cups employ different configurations to address how the contents, i.e., dirt and debris, are emptied. Some dirt cups use a lid detachably or rotatably mated with the upper portion of the dirt cup. Such a configuration requires the dirt cup to be inverted to empty the contents after removing or opening the lid. Other dirt cups employ a lid detachably or rotatably mated to the lower portion of the dirt cup, which allows the contents of the dirt cup to fall out with the assistance of gravity after the user removes or opens the lid. Other dirt cup lid configurations are also possible.
The lid, whether top- or bottom-mounted as described above, typically is secured to the dirt cup in some manner such that it remains in a closed position during the operation of the vacuum cleaner. The lid typically must be released to open it, and can only be opened when the cup is released from the housing. The lid typically is attached to the cup by a securing mechanism, such a latching mechanism, that must be actuated to release the lid. Various types of latching mechanisms are well known in the art. Examples of such mechanisms include, but are not limited to, friction fits, interference fits, bayonet fittings, clasps, hasps, clips, latches, and screws. Ideally, the latching mechanism should be easily manipulated by the user.
Some lid latching mechanisms employ a remote actuator that allows the user to actuate the mechanism from a location removed from the lid itself. For example, a cable may be used to remotely pull a pin or move a latch that holds the lid in place. The use of a stick or rod as an actuator to release or actuate the latching mechanism is also well known. The user typically actuates such an actuator mechanism by applying a downward force to the actuator causing the actuator to apply a force to the latching mechanism. This force drives the latching mechanism away from its attachment point or otherwise disengages the latching mechanism, to allow the lid to open, and also applies a force to the lid structure to move the lid away from the dirt cup. Other lid and lid latch actuation means are also known. Such remote actuators may be desired to allow the user to easily actuate the latching mechanism, from a location where it is less likely for dirt in the cup to contact the user. For example, a remote actuator may transmit the opening force from the top of the dirt cup, to open a lid at the bottom of the dirt cup.
Often, a hinge mechanism is used in conjunction with a latching mechanism to attach the lid to the dirt cup. This allows the lid to open to allow access to the interior of the dirt cup and allows the lid to remain attached to the dirt cup. The hinge mechanism typically is located opposite the locking mechanism. Once the locking mechanism is actuated and the lid is released, the lid will be supported by the hinge mechanism and remain attached to the dirt cup.
Exemplary dirt cup lid mechanisms that include locking and/or latching mechanisms, along with actuators, are shown in U.S. Pat. Nos. 3,055,039; 6,192,550; 6,991,666; 7,014,675; and 7,175,682, the contents of which are hereby incorporated by reference.
While various prior art devices, such as those described above, are known in the art, there exits a need to provide alternatives to such devices.
SUMMARY OF THE INVENTIONIn a first exemplary aspect, there is provided a vacuum cleaner dust cup having a cup with a sidewall surrounding an open bottom end, and a shelf extending from the sidewall, a lid pivotally connected to the cup adjacent the open bottom end by a hinge. The lid is movable about the hinge between a first position in which the lid substantially covers the open bottom end of the cup, and a second position in which the lid does not substantially cover the open bottom end of the cup. A latch is attached to the lid at a location remote from the hinge, and has a contact surface adapted to engage the shelf to hold the lid in the first position. An actuator is mounted adjacent the cup sidewall, and is movable in a first direction to move the contact surface of the latch out of engagement with the shelf to allow the lid to move about the hinge to the second position. The actuator does not apply any substantial force to move the lid out of the first position.
In another exemplary aspect, there is provided a vacuum cleaner dust cup having a cup with a sidewall surrounding an open bottom end and a lid pivotally connected to the cup adjacent the open bottom end by a hinge. The lid is movable about the hinge between a first position in which the lid substantially covers the open bottom end of the cup, and a second position in which the lid does not substantially cover the open bottom end of the cup. A latch is attached to the lid at a location remote from the hinge, and is configured to selectively engage the cup to hold the lid in the first position. An actuator is mounted adjacent the cup sidewall, and is movable in a first direction to disengage the latch from the cup to thereby allow the lid to move about the hinge to the second position. An air passage extends through the cup and terminates adjacent the open bottom end of the cup. The lid has a lid opening positioned to abut the air passage when the lid is in the first position. The lid is elastically deformed by contact with the air passage when the lid is in the first position, thereby generating a restoring force that biases the lid away from the first position.
In still another exemplary aspect, there is provided a vacuum cleaner dust cup having a cup with a vertically-extending sidewall surrounding an open bottom end, and a lid pivotally connected to the cup adjacent the open bottom end by a hinge. The lid is movable about the hinge between a first position in which the lid substantially covers the open bottom end of the cup, and a second position in which the lid does not substantially cover the open bottom end of the cup. A latch is attached to the lid at a location remote from the hinge, and is configured to selectively engage the cup to hold the lid in the first position. An actuator is mounted adjacent the cup sidewall, and includes a first member located generally adjacent the sidewall, and a second member movably attached to the first member. The first member is movable in a generally vertical direction. The second member has a contact surface that is adapted to move in a direction generally perpendicular to the sidewall as the first member moves in the generally vertical direction. The second member is positioned to disengage the latch from the cup when the contact surface has moved a predetermined distance from the sidewall.
The recitation of this summary of the invention is not intended to limit the claimed invention. Other aspects, embodiments, modifications to and features of the claimed invention will be apparent to persons of ordinary skill in view of the disclosures herein. Furthermore, this recitation of the summary of the invention, and the other disclosures provided herein, are not intended to diminish the scope of the claims in this or any prior or subsequent related or unrelated application.
BRIEF DESCRIPTION OF THE DRAWINGSThe present invention is described in detail with reference to the examples of embodiments shown in the following figures in which like parts are designated by like reference numerals.
FIG. 1 depicts an exemplary vacuum cleaner with which embodiments of the invention may be used.
FIG. 2A is a fragmented cutaway view of a dirt cup having a lid and lid latch according to a first embodiment, in which the latch is shown in the closed position.
FIG. 2B is a fragmented cutaway view of the dirt cup ofFIG. 2A, shown with the lid and latch in an opened position.
FIG. 3A is a detail view of the lid latch ofFIG. 2A shown in the latched position.
FIG. 3B is a detail view of the lid latch ofFIG. 2A shown in the unlatched position, but with the lid still closed.
FIG. 4A is a detail view of an alternative lid latch assembly according to an alternative exemplary embodiment, shown in the latched position.
FIG. 4B is a detail view of the lid latch assembly ofFIG. 4A, shown partially actuated.
FIG. 4C is a detail view of the lid latch assembly ofFIG. 4A, shown in the unlatched position, but with the lid still closed.
FIG. 5 is a fragmented isometric view of one exemplary embodiment of the bottom of the outlet air passage of the dirt cup assembly ofFIG. 2A.
FIG. 6 is a fragmented isometric view of an alternative exemplary embodiment of a bottom of the outlet air passage of the dirt cup assembly ofFIG. 2A.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTIONSThe present disclosure provides numerous inventive features relating to a latch mechanism. The latch mechanism may be used as a feature for a dirt cup for a vacuum cleaner. Accordingly, the latch mechanism may be configured to release a bottom lid of a vacuum cleaner dirt cup. While the embodiments of latch mechanisms described herein are provided in the context of a dirt cup for a vacuum cleaner, the invention may be used in other applications where a lid or other closure requires are latching and/or releasing mechanism. In addition, various features and alternative embodiments of the invention are described with reference to their exemplary use in certain particular embodiments, but it will be readily appreciated that the features could alternatively be mixed in other combinations in other embodiments. Furthermore, the various features described herein may be used separately from one another or in any suitable combination. The invention includes the foregoing and other variations, as will be appreciated by persons of ordinary skill in the art in view of the present disclosure. The present disclosure illustrating various exemplary embodiments is not intended to limit the invention in any way.
FIG. 1 illustrates a typicalupright vacuum cleaner10 with which embodiments of the present invention may be used. Thevacuum cleaner10 includes a base12 that is supported bywheels14 at the rear, and wheels (not shown) or another support surface at the front. Thebase12 includes a downwardly-facinginlet nozzle13, as well know in the art. The base12 may include aheight adjustment mechanism16, as known in the art. Arear housing17 is pivotally connected to thebase12. The rear housing includes agrip20 for directing thevacuum cleaner10, and may include asuction hose22 for cleaning off the floor, apost-motor filter24, and a dirt cup assembly19 comprising alid58 and acup18. Afilter26, located within the cup, fluidly covers anoutlet passage28 that passes through the middle of thecup18 to direct air downward to the inlet of a vacuum fan (not shown). The dirt cup assembly19, including thelid58 andcup18, may be removably connected to the remainder of therear housing17. Alternatively, only thecup18 may be removable. Vacuum cleaners of this and other types are known in the art, and shown, for example, in U.S. Pat. Nos. 6,829,804 and 7,544,244, which are incorporated herein by reference.
It will be understood that other embodiments of the invention may be used in the foregoing or other kinds of upright vacuum cleaner, or in autonomous vacuums, canister vacuum cleaners, central vacuum cleaners, and so on. In autonomous vacuums, the dirt cup and inlet nozzle are mounted on a vehicle frame, and in canister and central vacuum cleaners, the base is replaced by an inlet nozzle that is connected to a suction source and dirt receptacle by a flexible hose, as opposed to a pivoting joint. U.S. Pat. Nos. 5,781,960, 5,813,085 and 6,502,277 provide examples of such devices, and are incorporated herein.
A first exemplary embodiment of the invention is illustrated inFIGS. 2A and 2B, which illustrate a removabledirt collection assembly200 for a vacuum cleaner. Theassembly200 includes adirt cup202, that is closed at the top by afilter basket204 and a removableupper cover206. Thedirt cup202 may be, but is not required to be, generally, cylindrical. Thedirt cup202 is illustrated with a portion of its central region removed to make the illustration more compact, but it will be understood that thedirt cup202 may have any suitable length. The bottom of thedirt cup202 is closed by alid208, such as described below. Thefilter basket204 includes anair outlet passage210 that directs cleaned air to acentral hole212 through thelid208. Theoutlet passage210 may include acage211 that protrudes from the lower end, such as shown inFIG. 5. In such an embodiment, thecage211 protrudes into thelid hole212, as shown inFIG. 2A, which helps center the parts and also prevents large particles or objects from passing through thehole212. Aseal seat213 may surround thecage211 to receive aseal236 such as the ones discussed below. In an alternative embodiment, such as shown inFIG. 6, thecage211 may be replaced by a simple cylindrical or taperedsection602 that extends from the bottom of theoutlet passage210 to help center theoutlet passage210 in thehole212. It is believed that providing a protrusion on theoutlet passage210 is beneficial to help align the various parts, and will help prevent assembly when the parts are misaligned, which could result in poor performance and the ingestion of dirt directly into the vacuum fan (not shown). In addition, the use of a protrusion facilitates the use of abottom lid208 having a flat interior (i.e., dirt-facing) surface, which is useful to help prevent dirt from clinging to thelid208 when it is opened for emptying. Although these features are useful, they are not necessary in all embodiments, and in other embodiments a cage, cylindrical tapered section, or other structure to help orient the parts may not be provided.
Afilter214 is provided in the filter basked204 to cover theair outlet passage210. In this exemplarydirt collection assembly200, the air enters thedirt cup202, swirls around the filter basket in a cyclonic manner, and eventually passes through aperforated wall204aof thefilter basket204, passes through thefilter214, and then exits via theair outlet passage210. In other embodiments, other filtration systems may be used, as known in the art.
As noted above, thedirt cup202 anddirt collection assembly200 may be part of an upright, canister, central or any other type of vacuum cleaner as is well known in the art. In other embodiments, only thedirt cup202 may be removable, and thelid206, filter basket204 (if used) and outlet210 (if used) may remain in place on the cleaner, or be removable with thedirt cup202.
FIGS. 3A and 3B show, in greater detail, alatch assembly300 that may be used with the foregoingdirt cup202 andbottom lid208, or with other embodiments of the invention. Theexemplary latch assembly300 includes anactuator216, alatch218, and ashelf220. Theactuator216 may be located generally adjacent to an exterior surface of the cup sidewall. Theactuator216 is mounted such that it may slide along the length of thecup202 towards thelid208. Theactuator216 may be constrained to prevent it from moving away from the cup sidewall, or in directions other than generally towards and away from thelid208. For example, theactuator216 may be mounted within one ormore sleeves218 that are attached to or integrally formed with the sidewall112. It should be appreciated that theactuator216 may be mounted to thecup202 in a variety of configurations and locations. A remote actuating mechanism, such as aremote button219 formed on the end of theactuator216, a series of levers or abutting rods, a cable, and so on, may be employed with theactuator216. Aspring222 may be provided to bias theactuator216 away from thelid208 and into a resting position during periods of nonuse.
Thelatch218 may be located generally vertically below a lower end224 of theactuator216. Theexemplary latch218 has ahead226 which may optionally have a generally triangular cross section, such as shown. In the exemplary embodiment, thehead226 has a contact surface228 (seeFIG. 3B). Thecontact surface228 rests against theshelf220 to hold thelatch218 in place adjacent thedirt cup202. Thecontact surface228 andshelf220 preferably are arranged to be flat against one another, but this is not strictly required. In addition theshelf220 and/or thecontact surface228 may be inclined so that thelatch218 will release—rather than break—if a user pulls downward on thelid208 without first attempting to release thelatch218. Theshelf220 may be formed as part of the cup sidewall, formed separately and attached to thecup202, or detachably mounted to thecup202.
Thelatch218 is attached to one side of thelower lid208. At the other side, thelid208 may be pivotally attached to thedirt cup202 by ahinge230. Thus formed, thelid208 provides a pivoting door through which contents of thedirt cup202 can be released. In such an embodiment, thedoor208 is pivotally mounted at one side of thedirt cup202 by the hinge230 (which may comprise any suitable hinge, such as a simple pin in a hole, as known in the art), and secured in sealing contact with the bottom edge of thedirt cup202 by thelatch218. Thehinge230 preferably is remote from thelatch218, to provide at least two spaced connection points between thelid208 and thecup202. For example, the hinge may be located on the opposite side of thecup202 as thelatch218. Of course, more than one latch may be used, and the latch or latches need not be directly opposite thehinge230.
In the closed position shown inFIGS. 2A and 3A, thelatch218 engages theshelf220, and a friction and/or vector forces keep thelatch218 in place and the lid closed. When a user desires to open the lid, thelatch218 must be disengaged from contact with theshelf220. To do so, theactuator216 is urged towards thelatch218 by the user exerting a downward force directly upon theactuator216, which may be done via theactuator button219 or other any other suitable operating mechanism. As theactuator216 is urged downward, its lower end224 contacts thehead226 of thelatch218. As can best be seen inFIG. 3A, thehead226 may have aninclined surface302. The lower end224 of theactuator216 may have a rounded or beveled shape that slides on theinclined surface302, but it is more preferable for the end224 of theactuator216 to be essentially squared off so that only an edge or relatively small surface of the actuator216 contacts theinclined surface302. Upon further downward movement, the lower end224, theactuator216 wedges between thedirt cup202 and theinclined surface302, translating the downward force of theactuator216 into horizontal movement of thelatch218. This movement flexes thelatch218 outwards axially with respect to the axis of thedirt cup302, and approximately perpendicular to the direction of movement of theactuator216.FIG. 3B is an exemplary illustration of this motion. In this Figure, Arrow D1 shows the general direction of movement of theactuator216, and Arrow D2 shows the general direction of movement of thelatch218. The amount of force required to flex thelatch218 may be modified by adjusting the shape of thehinge218, as will be appreciated by persons of ordinary skill in the art. While the illustratedlatch218 uses a living hinge (i.e., a flexible portion that allows pivoting movement), it will be understood that thelatch218 may include a true mechanical pivot having a pivot pin and a spring to bias thelatch218 into the latched position.
Once theactuator216 is fully depressed, as illustrated inFIG. 3B, the actuator's lower end224 rests upon theshelf220. At this point, thelatch218, specifically thehead226, is flexed outward and beyond face contact with theshelf220, and thelid208 is free to open. In addition, if theactuator216 is approximately the same width as theshelf220, it will apply no further opening force to thelatch218. In such an embodiment, theactuator216 generally only applies a force to disengage thelatch218 that holds the lid closed, but does not apply any force to actually open thelid208. In such an embodiment, other forces, such as gravity or the resilient forces described further below apply all of the force necessary to open thelid208.
Aperimeter seal232, mounted around the circumference of the door208 (or to the bottom edge of the dirt cup202), may be provided to help prevent dirt and air from passing between thelid208 and thedirt cup202. The seal may be constructed of any suitable material, such as rubber, silicone, flexible plastic, and so on. Releasing thelatch218 provides a way to empty thedirt cup202 of collected dirt and dust. Theperimeter seal232 may seal between the parts in any suitable way. For example, as shown, theseal232 may include acompression seal232athat is compressed axially between thecup202 andlid208 by the force of pressing thelid208 in place, and a wiping or lip seal232bthat slides against the inner wall of thedirt cup202 and is compressed thereto when thelid208 is closed. Perimeter sealing arrangements such as these are known in the art. It has been found, however, that typical perimeter seals, and other kinds of dirt cup lid seal, often tend to bind the lid to the cup, making it difficult to open the lid to empty the dirt cup. It is believed that part of this binding force is caused by tactile adhesion between the seal and the cup, and another part of this binding force is caused by the tendency of the lip seal232bto expand against the inner wall of thecup202, and slide along the cup wall over a distance before thelid208 can pivot freely with respect to thecup202.
To address the problem with seals and debris holding the lid closed, in many instances, the prior art has provided a pushrod-type actuator that not only disengages the latch that holds the lid in place, but also pushes against the lid to drive it open against the binding forces applied by the lid seal(s). Such designs typically require the user to drive the actuator through an additional distance to complete the opening procedure, which may result in a failed attempt to open the lid if the user does not fully depress the actuator through its relatively long travel path. In addition, in such systems the user may apply the opening force too slowly to overcome the friction between the seal and the cup (which can be exacerbated by the presence of dirt that helps bind the seal), resulting in a failed opening. Conversely, the user may apply the opening force too quickly or with too great a force, potentially opening the lid in such a way that the dirt in the cup escapes with less control than may be desired. The additional travel distance required for the actuating rod can be lesser or greater, depending on the circumstances, but it is believed that the use of lip seals that contact the inner walls of the dirt cup require a greater travel distance for the pushrod to continue applying force until the lip seal is finally clear of the cup walls.
In order to alleviate the need for the user to manually apply a force to open the cup lid, theactuator216 may be only wide enough to move thelatch218 out of engagement with thecup202, but not shaped to apply any downward force on thelid208 after thelatch218 is released, such as described above. In such a case, gravity or other forces may be relied upon to open thelid208 against friction forces that hold thelid208 closed, but the friction generated by lip seals is expected, in most instances, to hold thelid208 closed even against gravity. Thus, and additional force may be needed to successfully and reliable open thelid208. In one embodiment, a spring (not shown), such as thespring222 used to bias theactuator216 to its inactive position, may be located between thelid208 and thecup202 to force thelid208 open once thelatch218 is clear of theshelf220. In embodiments in which acentral air passage210 directs the air through anoutlet opening212 through thelid208, additional provisions may be made to apply a force to open thelid208. For example, in the shown embodiment, theoutlet passage210 includes acompression seal236 that seals between theoutlet passage210 and thelid208. Thisseal236 may be formed on either thepassage210 or thelid208, and is shown in the exemplary embodiment being formed on thepassage210. Thecompression seal236 andperimeter seal232 may be molded of a flexible thermoplastic elastomer that retains its “as-molded” memory of shape. Thus, when thelid208 is closed, theseals232,236 are compressed to generate restoring forces that tend to drive thelid208 away from thecup202 as soon as thelatch218 is released. Thus, according to this exemplary embodiment, theseals232,236 are designed to function as springs, exerting a spring force against the closure members following compression thereof. When thelatch218 is released, theseals232,236 (or either one of the seals, if only one is used), drives thelid208 open to allow the cup's contents to be emptied and to allow the user to perform other functions that require access to the interior of the dirt cup, such as replacing a filter contained in the dirt cup. Preferably, the opening force generated by theseals232,236 is applied over a sufficient distance to move thelid208 until at least the portion of any lip seal opposite the hinge is clear of the cup to help ensure the lid opening. This is illustrated inFIG. 2B, which shows the side of thecompression seal236 surrounding theoutlet passage210 still in contact with and thus applying a restoring force to thelid208, until theperimeter seal232 is fully clear of thecup202 at a location opposite thehinge230.
The restoring force generated by theseals232,236 also may apply a downward force to thelatch218 when thelid208 is closed, generating friction between theshelf220 and the latchingsurface228 to assist in keeping thelid208 securely closed.
While exemplary embodiments may work effectively as described above, due to manufacturing tolerances of the parts, potential wear of components over repeated release operations, and interference that may be caused by dirt, a release handle234 (shown only inFIG. 2A) may be added to the outer edge of thedirt cup lid208. Such ahandle234 may be positioned anywhere on thelid208, but preferably is located where forces applied to thehandle234 tend to move thelatch218 out of engagement with theshelf220 before opening thelid208. For example, as shown inFIG. 2A, thehandle234 is located on thelatch218, so that a downward force on thelatch218 will tend to rotate thelatch218 out of engagement with theshelf220. In the event theactuator216 does not force thelatch218 beyond theshelf220, or if the restoring force in theseals232,236 is insufficient to overcome friction to open thelid208, thehandle234 allows the user to open the lid. Thehandle234 also may be used to assist in closing and securing the lid.
In other exemplary embodiments, the outlet passage210 (or its seal236) may be formed such that it contacts thelid208 at a point where thelid208 must be elastically deformed somewhat in order to engage thelatch218 with theshelf210. Doing so generates a restoring force in thelid208, effectively converting thelid208 into a spring that tends to open itself as thelatch218 is released. The location of such deformation can be controlled by providing flexible regions in the lid,208, such as a relatively flexible annular ring surrounding theoutlet212, and the effect of such flexing on the establishment of a suitable perimeter seal between thecup202 and thelid208 should be considered when using such an embodiment. In addition, in such an embodiment, or in any embodiment in which a restoring force is generated in the parts, consideration should be given to whether the restoring force will diminish with repeated engagements and disengagements of the latch, and whether such forces will induce creep or cold flow in the material during long storage periods. Where stored restoring forces are great, materials that resist cold flow or creep may be preferred.
A further exemplary embodiment of the invention is illustrated inFIGS. 4A-4C, which illustrate analternative latch assembly400 that may be used in the foregoing or any other suitable dirt cup. As with the latch previously described, thelatch assembly400 ofFIGS. 4A and 4B holds alid408 in place against adirt cup402.FIGS. 4A and 4B illustrate thelatch assembly400 in a latched position in which it holds alid408 closed.FIG. 4C illustrates thelatch assembly400 in a disengaged position, in which thelid408 is free to open under a suitable force, such as the force of gravity, a spring, restoring forces in seals, and so on.
Theexemplary latch assembly400 includes acup402, anactuator416, alatch418, ashelf420, and acompressible lip seal432. Thecup402 may have any shape, such as generally cylindrical, with a top plane and a bottom plane. The bottom plane is covered by alid408. As with the previous embodiment, theactuator416 may be located adjacent an exterior surface thecup402, and mounted to slide toward thelid408. As before, thelatch418 may be attached to the lid and have ahead426 that contacts theshelf420.
In the embodiment ofFIGS. 4A-4C, thelower end424 of theactuator416 is narrower than theshelf420. Although theactuator416 may be moved between the cup wall and thelatch head426, it is not wide enough, alone, to displace thehead426 far enough to disengage it from theshelf420. To provide the force necessary to move thehead426 out of engagement with theshelf420, acam430 is pivotally connected to the bottom of theactuator416. Thecam430 may be positioned between two legs (only one is visible in the cross-section view of the Figures) depending from the bottom of theactuator416, and pivotally mounted on ashaft434 that extends between the two legs, but other suitable pivoting arrangements may be used. Thecam416 may be molded of a low surface tension plastic, such as acetal, or any other suitable material like metal or other plastics. Thecam416 may be designed to rotate through a limited range of motion, so that it does not move into a position in which it does not operate as described below. Rotation travel stops, as are well-known in the art, may be provided for this purpose. According to exemplary embodiments, thecam416 is designed to rotate through an approximately 45 degree range of motion during normal operation of the latch mechanism as shown and described.
As shown inFIG. 4A, thecam430 includes aradial protrusion432 that extends further from the cam's pivot axis than other parts of thecam430. When theactuator416 is in its resting position above thelatch head426 as shown inFIG. 4A, the protrusion extends generally towards thehead426, but hangs at a downward angle. As theactuator416 is moved downward, thecam protrusion426 eventually contacts thehead426 and may begin moving thehead426 away from thecup402, such as shown inFIG. 4B. The angles of the contact surfaces between theprotrusion432 andhead426 are selected such that friction between these parts does not cause thecam430 to rotate towards thehead426 until the cam protrusion432 (or some other part of the cam430) contacts theshelf420. Once thecam430 contacts theshelf420, contact between thecam protrusion432 and theshelf420 causes thecam430 to rotate towards the latch head426 (counterclockwise in these Figures). Further downward movement of theactuator416 causes thecam430 to continue to rotate until theprotrusion432 has pushed thelatch head426 clear of theshelf420, such as shown inFIG. 4C. At this point, thelid408 may be opened by gravity or other forces, such as forces generated by springs, seals or part flexure, as described above.
It will be appreciated that using the foregoing mechanism, the vertical force applied to move theactuator416 downward is entirely converted into a lateral force by the time theactuator416 bottoms out on theshelf420. This prevents the actuator416 from applying any downward force to thelatch418 that would tend to move thelid408 from the closed position to the open position. Instead, the opening force must be provided by other means, such as gravity, springs, stored restoring forces in elastic members, and so on. While such force isolation is preferred, it is not strictly necessary in all embodiments, and it is expected that a cam such as the one disclosed may be used to apply an opening force in other alternative embodiments.
In an alternative embodiment, theactuator416 may be sized such that it contacts the head, instead of thecam430 contacting the head, until contact with theshelf420 rotates thecam430 towards thehead426. In other embodiments, the cam may be replaced by a flexible end of the actuator. In still other embodiments, the cam maybe replaced by a separate part that expands laterally when it is pressed vertically by theactuator416, such as a an expanding “scissor” linkage or a pneumatic chamber that expands laterally when pressed vertically. Such a separate part (or even the illustrated cam), may be mounted on thecup402, instead of theactuator416. In still another embodiment, the cam may be replaced by wedge or other moving member that is interposed between the cup sidewall and the latch head and applies a force perpendicular to the cup wall to move the latch out of engagement with the shelf.
The present disclosure describes a number of new, useful and nonobvious features and/or combinations of features that may be used alone or together with cyclonic vacuum cleaners and other kinds of suction cleaning devices having a dirt cup to hold collected dirt and debris. The embodiments described herein are all exemplary, and are not intended to limit the scope of the inventions in any way. It will be appreciated that the inventions described herein can be modified and adapted in various ways and for different uses. For example, the latching mechanism and actuator may be located inside the dirt cup, such as on the inner cup wall or on the wall forming the outlet passage (if an outlet passage is provided). These and all other modifications and adaptations are included in the scope of this disclosure and the appended claims.