Patent Publication Number: US-2011056045-A1

Title: Dirt Cup Latch Mechanism

Description:
FIELD OF THE INVENTION 
     The 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 INVENTION 
     It 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 INVENTION 
     In 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 DRAWINGS 
       The 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 of  FIG. 2A , shown with the lid and latch in an opened position. 
         FIG. 3A  is a detail view of the lid latch of  FIG. 2A  shown in the latched position. 
         FIG. 3B  is a detail view of the lid latch of  FIG. 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 of  FIG. 4A , shown partially actuated. 
         FIG. 4C  is a detail view of the lid latch assembly of  FIG. 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 of  FIG. 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 of  FIG. 2A . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTIONS 
     The 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 typical upright vacuum cleaner  10  with which embodiments of the present invention may be used. The vacuum cleaner  10  includes a base  12  that is supported by wheels  14  at the rear, and wheels (not shown) or another support surface at the front. The base  12  includes a downwardly-facing inlet nozzle  13 , as well know in the art. The base  12  may include a height adjustment mechanism  16 , as known in the art. A rear housing  17  is pivotally connected to the base  12 . The rear housing includes a grip  20  for directing the vacuum cleaner  10 , and may include a suction hose  22  for cleaning off the floor, a post-motor filter  24 , and a dirt cup assembly  19  comprising a lid  58  and a cup  18 . A filter  26 , located within the cup, fluidly covers an outlet passage  28  that passes through the middle of the cup  18  to direct air downward to the inlet of a vacuum fan (not shown). The dirt cup assembly  19 , including the lid  58  and cup  18 , may be removably connected to the remainder of the rear housing  17 . Alternatively, only the cup  18  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 in  FIGS. 2A and 2B , which illustrate a removable dirt collection assembly  200  for a vacuum cleaner. The assembly  200  includes a dirt cup  202 , that is closed at the top by a filter basket  204  and a removable upper cover  206 . The dirt cup  202  may be, but is not required to be, generally, cylindrical. The dirt cup  202  is illustrated with a portion of its central region removed to make the illustration more compact, but it will be understood that the dirt cup  202  may have any suitable length. The bottom of the dirt cup  202  is closed by a lid  208 , such as described below. The filter basket  204  includes an air outlet passage  210  that directs cleaned air to a central hole  212  through the lid  208 . The outlet passage  210  may include a cage  211  that protrudes from the lower end, such as shown in  FIG. 5 . In such an embodiment, the cage  211  protrudes into the lid hole  212 , as shown in  FIG. 2A , which helps center the parts and also prevents large particles or objects from passing through the hole  212 . A seal seat  213  may surround the cage  211  to receive a seal  236  such as the ones discussed below. In an alternative embodiment, such as shown in  FIG. 6 , the cage  211  may be replaced by a simple cylindrical or tapered section  602  that extends from the bottom of the outlet passage  210  to help center the outlet passage  210  in the hole  212 . It is believed that providing a protrusion on the outlet passage  210  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 a bottom lid  208  having a flat interior (i.e., dirt-facing) surface, which is useful to help prevent dirt from clinging to the lid  208  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. 
     A filter  214  is provided in the filter basked  204  to cover the air outlet passage  210 . In this exemplary dirt collection assembly  200 , the air enters the dirt cup  202 , swirls around the filter basket in a cyclonic manner, and eventually passes through a perforated wall  204   a  of the filter basket  204 , passes through the filter  214 , and then exits via the air outlet passage  210 . In other embodiments, other filtration systems may be used, as known in the art. 
     As noted above, the dirt cup  202  and dirt collection assembly  200  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 the dirt cup  202  may be removable, and the lid  206 , filter basket  204  (if used) and outlet  210  (if used) may remain in place on the cleaner, or be removable with the dirt cup  202 . 
       FIGS. 3A and 3B  show, in greater detail, a latch assembly  300  that may be used with the foregoing dirt cup  202  and bottom lid  208 , or with other embodiments of the invention. The exemplary latch assembly  300  includes an actuator  216 , a latch  218 , and a shelf  220 . The actuator  216  may be located generally adjacent to an exterior surface of the cup sidewall. The actuator  216  is mounted such that it may slide along the length of the cup  202  towards the lid  208 . The actuator  216  may be constrained to prevent it from moving away from the cup sidewall, or in directions other than generally towards and away from the lid  208 . For example, the actuator  216  may be mounted within one or more sleeves  218  that are attached to or integrally formed with the sidewall  112 . It should be appreciated that the actuator  216  may be mounted to the cup  202  in a variety of configurations and locations. A remote actuating mechanism, such as a remote button  219  formed on the end of the actuator  216 , a series of levers or abutting rods, a cable, and so on, may be employed with the actuator  216 . A spring  222  may be provided to bias the actuator  216  away from the lid  208  and into a resting position during periods of nonuse. 
     The latch  218  may be located generally vertically below a lower end  224  of the actuator  216 . The exemplary latch  218  has a head  226  which may optionally have a generally triangular cross section, such as shown. In the exemplary embodiment, the head  226  has a contact surface  228  (see  FIG. 3B ). The contact surface  228  rests against the shelf  220  to hold the latch  218  in place adjacent the dirt cup  202 . The contact surface  228  and shelf  220  preferably are arranged to be flat against one another, but this is not strictly required. In addition the shelf  220  and/or the contact surface  228  may be inclined so that the latch  218  will release—rather than break—if a user pulls downward on the lid  208  without first attempting to release the latch  218 . The shelf  220  may be formed as part of the cup sidewall, formed separately and attached to the cup  202 , or detachably mounted to the cup  202 . 
     The latch  218  is attached to one side of the lower lid  208 . At the other side, the lid  208  may be pivotally attached to the dirt cup  202  by a hinge  230 . Thus formed, the lid  208  provides a pivoting door through which contents of the dirt cup  202  can be released. In such an embodiment, the door  208  is pivotally mounted at one side of the dirt cup  202  by the hinge  230  (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 the dirt cup  202  by the latch  218 . The hinge  230  preferably is remote from the latch  218 , to provide at least two spaced connection points between the lid  208  and the cup  202 . For example, the hinge may be located on the opposite side of the cup  202  as the latch  218 . Of course, more than one latch may be used, and the latch or latches need not be directly opposite the hinge  230 . 
     In the closed position shown in  FIGS. 2A and 3A , the latch  218  engages the shelf  220 , and a friction and/or vector forces keep the latch  218  in place and the lid closed. When a user desires to open the lid, the latch  218  must be disengaged from contact with the shelf  220 . To do so, the actuator  216  is urged towards the latch  218  by the user exerting a downward force directly upon the actuator  216 , which may be done via the actuator button  219  or other any other suitable operating mechanism. As the actuator  216  is urged downward, its lower end  224  contacts the head  226  of the latch  218 . As can best be seen in  FIG. 3A , the head  226  may have an inclined surface  302 . The lower end  224  of the actuator  216  may have a rounded or beveled shape that slides on the inclined surface  302 , but it is more preferable for the end  224  of the actuator  216  to be essentially squared off so that only an edge or relatively small surface of the actuator  216  contacts the inclined surface  302 . Upon further downward movement, the lower end  224 , the actuator  216  wedges between the dirt cup  202  and the inclined surface  302 , translating the downward force of the actuator  216  into horizontal movement of the latch  218 . This movement flexes the latch  218  outwards axially with respect to the axis of the dirt cup  302 , and approximately perpendicular to the direction of movement of the actuator  216 .  FIG. 3B  is an exemplary illustration of this motion. In this Figure, Arrow D 1  shows the general direction of movement of the actuator  216 , and Arrow D 2  shows the general direction of movement of the latch  218 . The amount of force required to flex the latch  218  may be modified by adjusting the shape of the hinge  218 , as will be appreciated by persons of ordinary skill in the art. While the illustrated latch  218  uses a living hinge (i.e., a flexible portion that allows pivoting movement), it will be understood that the latch  218  may include a true mechanical pivot having a pivot pin and a spring to bias the latch  218  into the latched position. 
     Once the actuator  216  is fully depressed, as illustrated in  FIG. 3B , the actuator&#39;s lower end  224  rests upon the shelf  220 . At this point, the latch  218 , specifically the head  226 , is flexed outward and beyond face contact with the shelf  220 , and the lid  208  is free to open. In addition, if the actuator  216  is approximately the same width as the shelf  220 , it will apply no further opening force to the latch  218 . In such an embodiment, the actuator  216  generally only applies a force to disengage the latch  218  that holds the lid closed, but does not apply any force to actually open the lid  208 . In such an embodiment, other forces, such as gravity or the resilient forces described further below apply all of the force necessary to open the lid  208 . 
     A perimeter seal  232 , mounted around the circumference of the door  208  (or to the bottom edge of the dirt cup  202 ), may be provided to help prevent dirt and air from passing between the lid  208  and the dirt cup  202 . The seal may be constructed of any suitable material, such as rubber, silicone, flexible plastic, and so on. Releasing the latch  218  provides a way to empty the dirt cup  202  of collected dirt and dust. The perimeter seal  232  may seal between the parts in any suitable way. For example, as shown, the seal  232  may include a compression seal  232   a  that is compressed axially between the cup  202  and lid  208  by the force of pressing the lid  208  in place, and a wiping or lip seal  232   b  that slides against the inner wall of the dirt cup  202  and is compressed thereto when the lid  208  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 seal  232   b  to expand against the inner wall of the cup  202 , and slide along the cup wall over a distance before the lid  208  can pivot freely with respect to the cup  202 . 
     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, the actuator  216  may be only wide enough to move the latch  218  out of engagement with the cup  202 , but not shaped to apply any downward force on the lid  208  after the latch  218  is released, such as described above. In such a case, gravity or other forces may be relied upon to open the lid  208  against friction forces that hold the lid  208  closed, but the friction generated by lip seals is expected, in most instances, to hold the lid  208  closed even against gravity. Thus, and additional force may be needed to successfully and reliable open the lid  208 . In one embodiment, a spring (not shown), such as the spring  222  used to bias the actuator  216  to its inactive position, may be located between the lid  208  and the cup  202  to force the lid  208  open once the latch  218  is clear of the shelf  220 . In embodiments in which a central air passage  210  directs the air through an outlet opening  212  through the lid  208 , additional provisions may be made to apply a force to open the lid  208 . For example, in the shown embodiment, the outlet passage  210  includes a compression seal  236  that seals between the outlet passage  210  and the lid  208 . This seal  236  may be formed on either the passage  210  or the lid  208 , and is shown in the exemplary embodiment being formed on the passage  210 . The compression seal  236  and perimeter seal  232  may be molded of a flexible thermoplastic elastomer that retains its “as-molded” memory of shape. Thus, when the lid  208  is closed, the seals  232 ,  236  are compressed to generate restoring forces that tend to drive the lid  208  away from the cup  202  as soon as the latch  218  is released. Thus, according to this exemplary embodiment, the seals  232 ,  236  are designed to function as springs, exerting a spring force against the closure members following compression thereof. When the latch  218  is released, the seals  232 ,  236  (or either one of the seals, if only one is used), drives the lid  208  open to allow the cup&#39;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 the seals  232 ,  236  is applied over a sufficient distance to move the lid  208  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 in  FIG. 2B , which shows the side of the compression seal  236  surrounding the outlet passage  210  still in contact with and thus applying a restoring force to the lid  208 , until the perimeter seal  232  is fully clear of the cup  202  at a location opposite the hinge  230 . 
     The restoring force generated by the seals  232 ,  236  also may apply a downward force to the latch  218  when the lid  208  is closed, generating friction between the shelf  220  and the latching surface  228  to assist in keeping the lid  208  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 handle  234  (shown only in  FIG. 2A ) may be added to the outer edge of the dirt cup lid  208 . Such a handle  234  may be positioned anywhere on the lid  208 , but preferably is located where forces applied to the handle  234  tend to move the latch  218  out of engagement with the shelf  220  before opening the lid  208 . For example, as shown in  FIG. 2A , the handle  234  is located on the latch  218 , so that a downward force on the latch  218  will tend to rotate the latch  218  out of engagement with the shelf  220 . In the event the actuator  216  does not force the latch  218  beyond the shelf  220 , or if the restoring force in the seals  232 ,  236  is insufficient to overcome friction to open the lid  208 , the handle  234  allows the user to open the lid. The handle  234  also may be used to assist in closing and securing the lid. 
     In other exemplary embodiments, the outlet passage  210  (or its seal  236 ) may be formed such that it contacts the lid  208  at a point where the lid  208  must be elastically deformed somewhat in order to engage the latch  218  with the shelf  210 . Doing so generates a restoring force in the lid  208 , effectively converting the lid  208  into a spring that tends to open itself as the latch  218  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 the outlet  212 , and the effect of such flexing on the establishment of a suitable perimeter seal between the cup  202  and the lid  208  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 in  FIGS. 4A-4C , which illustrate an alternative latch assembly  400  that may be used in the foregoing or any other suitable dirt cup. As with the latch previously described, the latch assembly  400  of  FIGS. 4A and 4B  holds a lid  408  in place against a dirt cup  402 .  FIGS. 4A and 4B  illustrate the latch assembly  400  in a latched position in which it holds a lid  408  closed.  FIG. 4C  illustrates the latch assembly  400  in a disengaged position, in which the lid  408  is free to open under a suitable force, such as the force of gravity, a spring, restoring forces in seals, and so on. 
     The exemplary latch assembly  400  includes a cup  402 , an actuator  416 , a latch  418 , a shelf  420 , and a compressible lip seal  432 . The cup  402  may have any shape, such as generally cylindrical, with a top plane and a bottom plane. The bottom plane is covered by a lid  408 . As with the previous embodiment, the actuator  416  may be located adjacent an exterior surface the cup  402 , and mounted to slide toward the lid  408 . As before, the latch  418  may be attached to the lid and have a head  426  that contacts the shelf  420 . 
     In the embodiment of  FIGS. 4A-4C , the lower end  424  of the actuator  416  is narrower than the shelf  420 . Although the actuator  416  may be moved between the cup wall and the latch head  426 , it is not wide enough, alone, to displace the head  426  far enough to disengage it from the shelf  420 . To provide the force necessary to move the head  426  out of engagement with the shelf  420 , a cam  430  is pivotally connected to the bottom of the actuator  416 . The cam  430  may be positioned between two legs (only one is visible in the cross-section view of the Figures) depending from the bottom of the actuator  416 , and pivotally mounted on a shaft  434  that extends between the two legs, but other suitable pivoting arrangements may be used. The cam  416  may be molded of a low surface tension plastic, such as acetal, or any other suitable material like metal or other plastics. The cam  416  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, the cam  416  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 in  FIG. 4A , the cam  430  includes a radial protrusion  432  that extends further from the cam&#39;s pivot axis than other parts of the cam  430 . When the actuator  416  is in its resting position above the latch head  426  as shown in  FIG. 4A , the protrusion extends generally towards the head  426 , but hangs at a downward angle. As the actuator  416  is moved downward, the cam protrusion  426  eventually contacts the head  426  and may begin moving the head  426  away from the cup  402 , such as shown in  FIG. 4B . The angles of the contact surfaces between the protrusion  432  and head  426  are selected such that friction between these parts does not cause the cam  430  to rotate towards the head  426  until the cam protrusion  432  (or some other part of the cam  430 ) contacts the shelf  420 . Once the cam  430  contacts the shelf  420 , contact between the cam protrusion  432  and the shelf  420  causes the cam  430  to rotate towards the latch head  426  (counterclockwise in these Figures). Further downward movement of the actuator  416  causes the cam  430  to continue to rotate until the protrusion  432  has pushed the latch head  426  clear of the shelf  420 , such as shown in  FIG. 4C . At this point, the lid  408  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 the actuator  416  downward is entirely converted into a lateral force by the time the actuator  416  bottoms out on the shelf  420 . This prevents the actuator  416  from applying any downward force to the latch  418  that would tend to move the lid  408  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, the actuator  416  may be sized such that it contacts the head, instead of the cam  430  contacting the head, until contact with the shelf  420  rotates the cam  430  towards the head  426 . 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 the actuator  416 , 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 the cup  402 , instead of the actuator  416 . 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.