Patent Publication Number: US-9885189-B2

Title: Apparatus and method for smoothing drywall mud

Description:
FIELD 
     This invention relates to drywall finishing tools and methods for using same, and in particular to handheld tools for smoothing and blending drywall mud. 
     BACKGROUND 
     Drywall (sometimes referred to as gypsum board, plasterboard, wallboard, or other names) is a commonly-used material in construction projects, particularly for the installation of interior walls and ceilings. Drywall sheets are typically attached to studs with screws, nails, or other fasteners, thereby forming a wall or ceiling covering composed of edge-adjacent drywall sheets. Seams between edge-adjacent drywall sheets are typically covered with tape, and corners between sheets may be covered with corner beads (usually metal and paper L-shaped structures). Tape, corner beads, countersunk screws, and other irregularities in the surface of the drywall are covered by a joint compound, often referred to as “mud”. 
     Mud is often applied in multiple layers, with each layer given time to dry (or cure) and then sanded smooth before the next layer is applied. Sanding dried mud to achieve a substantially seamless, smooth surface which conceals underlying irregularities is generally a lengthy and labor-intensive process. For example, mud is commonly sanded by use of sandpaper, which can take a significant amount of time, require significant physical exertion, and result in significant quantities of airborne dust. The dried mud is commonly feathered (i.e. thinner towards the edges) so that it blends in with the surrounding drywall sheets. Correctly blending the mud often requires a certain degree of experience, since over-sanding an area is a common mistake and may result in damage to the drywall and/or a need to reapply mud. 
     Accordingly, there is a general desire for apparatus and methods for smoothing dried drywall mud. 
     SUMMARY 
     An aspect of the present disclosure provides apparatus for smoothing drywall mud. The apparatus comprises a body having a support and a flexible blade assembly engaged with the body. The blade assembly extends in a transverse direction and is flexible in a flexion direction orthogonal to the transverse direction. The blade assembly has first and second locations which are spaced apart in the transverse direction and which are substantially fixed in the flexion direction relative to the body. The apparatus further comprises a blade adjustment mechanism adjustably coupled between the support and a portion of the blade assembly located between the first and second locations in the transverse direction. The blade adjustment mechanism is adjustable to flex the portion of the blade assembly in the flexion direction. 
     In some embodiments, the blade adjustment mechanism comprises a displacement member that is movable relative to the support in the flexion direction and is in contact with the portion of the blade assembly. In some embodiments, the displacement member is movable, relative to the support, to a first position wherein contact between the displacement member and the portion of the blade assembly causes a first deformation of the portion of the blade assembly and to a second position wherein the contact between the displacement member and the portion of the blade assembly causes a second deformation of the portion of the blade assembly. In some embodiments, the flexion direction is away from the support. 
     In some embodiments, the apparatus comprises one or more blade biasing mechanisms. Each blade biasing mechanism is anchored to the blade assembly and biases the blade assembly towards the support. In some embodiments, biasing the blade assembly towards the support comprises biasing the blade assembly in an opposing direction opposed to the flexion direction. 
     In some embodiments, at least one of the one or more blade biasing mechanisms comprises a rod extending through an aperture in the support. The rod has a first end anchored to the blade assembly and a second end opposite the first end. The aperture in the support is located between the first and second ends. The at least one of the one or more blade biasing mechanisms also comprises a head at the second end of the rod. The head has a width greater than a width of the rod. The at least one of the one or more blade biasing mechanisms also comprises a spring engaged between the head and the support. The spring biases the head away from the support. 
     In some embodiments, the one or more blade biasing mechanisms comprise a first biasing mechanism and a second biasing mechanism. The first biasing mechanism is located transversely between the blade adjustment mechanism and the first location. The second biasing mechanism is located transversely between the blade adjustment mechanism and the second location. 
     In some embodiments, the blade assembly is engageable with a plurality of blades. The plurality of blades comprise a first blade extending in the transverse direction and a second blade extending in the transverse direction and spaced apart from the first blade in the flexion direction. In some embodiments, the first blade comprises a rough edge for shaving drywall mud. The rough edge comprises one or more channels for the passage of excess drywall mud. The second blade comprises a smooth edge for smoothing drywall mud. The smooth edge is relatively smooth in comparison to the rough edge. 
     In some embodiments, the blade assembly comprises one or more connectors. Each of the one or more connectors is engageable with each of the plurality of blades. The one or more connectors are engageable with the plurality of blades at the first and second locations and at a third location of the blade assembly where the blade displacement member is coupled to the blade assembly. In some embodiments, the apparatus comprises one or more biasing mechanisms. Each biasing mechanism is anchored to a connector of the one or more connectors at a biasing location of the blade assembly. The one or more connectors are engageable with the plurality of blades at the one or more biasing locations. 
     In some embodiments, the one or more connectors comprise a first connector engageable with the plurality of blades at the first location, a second connector engageable with the plurality of blades at the second location, and a third connector engageable with the plurality of blades at the third location. In some embodiments, the apparatus comprises a first biasing mechanism anchored to a first bias connector. The first bias connector is engageable with the plurality of blades at the first bias location. The apparatus further comprises a second bias mechanism anchored to a second bias connector. The second bias connector is engageable with the plurality of blades at a second bias location. The first and second bias mechanisms are configured to bias the plurality of blades towards the support at the corresponding first and second bias locations. In some embodiments, the first biasing location is located transversely between the blade adjustment mechanism and the first location. The second biasing location is located transversely between the blade adjustment mechanism and the second location. 
     In some embodiments, the one or more connectors comprise a plurality of rigid connectors and the blade assembly comprises one or more relatively flexible mounts connecting the one or more connectors. 
     In some embodiments, the first connector is slidably anchored to the body at the first location. The first connector has an engagement member receivable by a concavity defined in the body and the concavity extends substantially in the transverse direction. The engagement member is slidable in the transverse direction while received by the concavity. 
     In some embodiments, the apparatus comprises a handle assembly for engaging a handle extending in a handle direction, one or more support arms connected to the handle assembly and extending from the handle assembly to the body, and a handle biasing mechanism connected to the handle assembly and extending from the handle assembly to the body. The body is rotatably connected to each of the one or more support arms so that the body is rotatable about an axis parallel to the transverse direction. The handle biasing mechanism biases the body towards a rotational position wherein, when one or more blades are engaged with the blade assembly and a handle is engaged by the handle assembly, the one or more blades are offset from the handle direction by an offset angle. 
     In some embodiments, the displacement member comprises a screw threadably engaged with the support. The screw is rotatable to move in the flexion direction relative to the support. 
     An aspect of the present disclosure provides a method for smoothing drywall mud with a drywalling tool. The tool has a body, a flexible blade assembly extending in a transverse direction, and a blade adjustment mechanism adjustably coupled between a support of the body and a portion of the blade assembly. The flexible blade assembly is flexible in a flexion direction. The method comprises adjusting the blade adjustment mechanism to flex the portion of the blade assembly in the flexion direction, thereby imparting a curvature to one or more blades of the blade assembly. The method further comprises positioning the one or more blades of the blade assembly against a portion of drywall mud. The method further comprises advancing the one or more blades along the portion of drywall mud to smooth the portion of drywall mud. The smoothed portion of drywall mud has a shape corresponding to the curvature of the one or more blades. 
     In some embodiments, the blade adjustment mechanism comprises a displacement member that is in contact with the portion of the blade assembly. Flexing the portion of the blade assembly in the flexion direction comprises moving the displacement member, relative to the support, in the flexion direction from a first position to a second position. Contact between the displacement member and the portion of the blade assembly causes a deformation of the portion of the blade assembly. The method further comprises retaining the displacement member in the second position via engagement of the displacement member with the support. 
     In some embodiments, the displacement member is threadably engaged with the support and moving the displacement member comprises rotating the displacement member to move in the flexion direction relative to the support. In some embodiments, the blade adjustment mechanism comprises a displacement member that is in contact with the portion of the blade assembly, the tool comprises a biasing mechanism anchored to the blade assembly, and flexing the portion of the blade assembly in the flexion direction comprises moving the displacement member, relative to the support, in an opposing direction from a first position to a second position. The opposing direction opposes the flexion direction. Flexing the portion of the blade assembly also comprises biasing the blade assembly towards the support in the opposing direction with the biasing mechanism. Bias exerted by the biasing mechanism on the portion of the blade assembly causes a deformation of the portion of the blade assembly. 
     In some embodiments, advancing the one or more blades along the portion of drywall mud comprises advancing the first blade along the portion of drywall mud to provide a rough finish to the portion of drywall mud and, after advancing the first blade along the portion of drywall mud, advancing the second blade along the portion of drywall mud to provide a smooth finish to the portion of drywall mud. The smooth finish is relatively smooth in comparison to the rough finish. In some embodiments, the method comprises continuously smoothing a plurality of portions of drywall mud by advancing the first and second blades along the plurality of portions of drywall mud substantially simultaneously. 
     An aspect of the present disclosure provides another apparatus for smoothing drywall mud. The apparatus comprises a body, a flexible blade assembly movably engaged with the body, and one or more blade biasing mechanisms. The blade assembly extends in a transverse direction and is flexible in a flexion direction orthogonal to the transverse direction. The blade assembly has first and second locations which are spaced apart in the transverse direction and which are substantially fixed in the flexion direction relative to the body. Each blade biasing mechanism is anchored to the blade assembly and biases the blade assembly in the flexion direction. In some embodiments, the flexion direction is away from the body. 
     In some embodiments, at least one of the one or more blade biasing mechanisms comprises a rod having a first end anchored to the blade assembly and a second end opposite the first end and a spring engaged between the blade assembly and the body. The second end is retained in a cavity defined by the body. The spring biases the blade assembly away from the body and is retained by the rod. In some embodiments, the at least one of the one or more blade biasing mechanisms comprises a head engaged with the second end of the rod. The head is retained by the cavity. 
     In some embodiments, the body is pivotably engaged with the blade assembly and the one or more blade biasing mechanisms do at least one of: oppose pivoting movement of the body toward the blade assembly and amplify pivoting movement of the body toward the blade assembly. 
     In some embodiments, the blade assembly comprises one or more connectors. Each of the one or more connectors is engageable with one or more blades. The one or more blades are flexible in the flexion direction while engaged with the one or more connectors. In some embodiments, the one or more blade biasing mechanisms comprise a first biasing mechanism and a second biasing mechanism. The first biasing mechanism has a greater spring constant than the second biasing mechanism. In some embodiments, the first blade biasing mechanism is anchored to a first connector and the second blade biasing mechanism is anchored to a second connector. The first connector permits relatively less flexion of the one or more blades than the second connector. In some embodiments, the first blade biasing mechanism and first connector are located relatively transversely outwardly relative to the second blade biasing mechanism and second connector. In some embodiments, the one or more connectors comprise a plurality of rigid connectors and the blade assembly comprises one or more relatively flexible mounts connecting the one or more connectors. 
     Further aspects and example embodiments are illustrated in the accompanying drawings and/or described in the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate non-limiting example embodiments of the invention. 
         FIG. 1A  is a first perspective view of an example drywalling tool according to the present disclosure. 
         FIG. 1B  is a second perspective view of the example drywalling tool of  FIG. 1A  showing the tool from a different angle than  FIG. 1A . 
         FIG. 1C  is a third perspective view of the example drywalling tool of  FIG. 1A  showing the tool from a different angle than  FIGS. 1B and 1C . 
         FIG. 2A  is a plan view of the example drywalling tool of  FIG. 1A . 
         FIG. 2B  is a plan view of the example drywalling tool of  FIG. 1A  showing an opposing side of the tool relative to  FIG. 2A . 
         FIG. 3  is a side elevation view of the example drywalling tool of  FIG. 1A . 
         FIG. 4A  is a plan view of an example blade for the example drywalling tool of  FIG. 1A  having a relatively rough leading edge. 
         FIG. 4B  is a plan view of an example blade for the example drywalling tool of  FIG. 1A  having a relatively smooth leading edge. 
         FIG. 5A  is a front elevation view of the example drywalling tool of  FIG. 1A  while the blades of the tool are unflexed. 
         FIG. 5B  is a front elevation view of the example drywalling tool of  FIG. 1A  while the blades of the tool are flexed in a first direction by a displacement member. 
         FIG. 5C  is a front elevation view of the example drywalling tool of  FIG. 1A  while the blades of the tool are flexed in a second direction by biasing mechanisms. 
         FIG. 6  is a side elevation view of the example drywalling tool of  FIG. 1A  while being used to smooth dried drywall mud. 
         FIG. 7  is a side elevation cross-sectional view corresponding to  FIG. 6 , wherein the cross-section is taken through the displacement member. 
         FIG. 8  is a perspective view of another example drywalling tool according to the present disclosure. 
         FIG. 9  is a side elevation view of the example drywalling tool of  FIG. 8 . 
         FIG. 10  is a cross-sectional view of the example drywalling tool of  FIG. 8  taken along line B-B of  FIG. 9 . 
         FIG. 11A  is a front elevation view of the example drywalling tool of  FIG. 8 . 
         FIG. 11B  is a back elevation view of the example drywalling tool of  FIG. 8 . 
         FIG. 12A  is a plan view of the example drywalling tool of  FIG. 8 . 
         FIG. 12B  is a plan view of the example drywalling tool of  FIG. 8 , showing an opposing side relative to the view of  FIG. 12A . 
     
    
    
     DETAILED DESCRIPTION 
     Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive sense. 
     Aspects of the present disclosure provide apparatus and methods for smoothing drywall mud (which may include blending and/or feathering drywall mud). The apparatus provides a drywalling tool having one or more flexible blades to be applied to unfinished dried drywall mud. The blades may be selectively flexed by moving a displacement member relative to the body of the tool. The blades may be biased against the displacement member by biasing mechanisms. The tool may receive multiple blades, including a relatively rough-edged blade for a first pass across the drywall mud and a relatively smooth-edged blade for subsequent pass across the drywall mud. The blades may be kept in place with connectors which may be flexibly connected to allow for flexion. 
       FIGS. 1A, 1B and 1C  (collectively and individually, “ FIG. 1 ”),  FIGS. 2A and 2B  (collectively and individually, “ FIG. 2 ”) and  FIG. 3  provide several views of an example drywalling tool  1 . Drywalling tool  1  has a body  2  which engages a blade assembly  10 . In the depicted embodiment, body  2  comprises a blade assembly connector  4  for engaging blade assembly  10  and a frame  6  to which various other elements of tool  1  (such as guide  56  and handle assembly  40 , discussed below) are connected. In some embodiments, blade assembly connector  4  and frame  6  are integrally formed. In other embodiments, blade assembly connector  4  and frame  6  are permanently or removably attached. In still other embodiments, frame  6  may be omitted and other elements of tool  1  (if any) may connect directly or indirectly to blade assembly connector  4  and/or to other components of body  2 . Body  2  may be made of suitably rigid metal, plastic, wood, other materials and/or combinations thereof. 
     Blade assembly  10  comprises one or more blades  14 . Blade assembly  10  may be permanently or releasably connected to body  2 . For example, blade assembly  10  may comprise a cartridge insertable into or otherwise releasably connectable to blade assembly connector  4 . As another example, blade assembly  10  may be integrally formed with body  2 . 
     The example blade assembly  10  shown in  FIG. 1  receives one or more blades  14 , which are releasably connectable to and separately formed from blade assembly  10 . In some embodiments, blades  14  are integrally formed with and/or otherwise fixedly attached to blade assembly  10 . For example, blades  14  may be fixedly attached to blade assembly  10  by interlocking bolts and apertures. Blade assembly  10  may be provided with a full complement of blades  14  (e.g. three blades  14  in the case of the  FIG. 1  embodiment, but any suitable number of blades in other embodiments). However, blade assembly  10  may additionally or alternatively be provided with a number of blades  14  which is less than a full complement of blades  14 . In some cases, blade assembly  10  may be provided without blades  14 . In these cases (i.e. wherever blade assembly  10  comprises fewer than a full complement of blades  14 ), blade assembly  10  may receive one or more blades  14  to provide a full complement. 
     In at least the example embodiment of  FIG. 1 , blades  14  may be received and held in place by blade assembly  10  during use of tool  1 , and may be subsequently removed and/or replaced. Removal and/or replacement of blades  14  may be due to wear, in response to a user&#39;s needs, and/or for other reasons. For example, as will be discussed in greater detail below, blades  14  may be provided with a variety of types of leading edges  15 , and different leading edges may be preferable in different circumstances. A blade  14  with a relatively rough leading edge  15  may be used on a rough portion of drywall mud and/or to provide relatively coarse smoothing, and may be swapped out for a different blade  14  with a relatively smoother leading edge  15  when finishing a smoother portion of drywall mud and/or to provide relatively fine smoothing. 
     In some embodiments, blade assembly  10  houses a plurality of blades  14 . For example, blade assembly  10  may house blades  14   a ,  14   b , and  14   c  (referred to collectively and individually herein as blades  14 ), as shown in  FIGS. 1, 2, and 3 . In some embodiments, blades  14  are substantially identical. In some embodiments, one or more of the blades  14  are different than other blades  14 . In some embodiments, blades  14  are removable, replaceable and/or interchangeable. 
     For example, blade  14   a  may have a serrated, irregular, or otherwise non-smooth leading edge  15   a  suitable for shaving rough portions of drywall mud and/or to provide a relatively coarse smoothing. An example of such a blade  14   a  is shown in  FIG. 4A . As is discussed in greater detail below, as tool  1  is drawn across a portion of drywall mud, blade  14   a  may be the first to pass across the portion of drywall mud, thereby shaving the portion of drywall mud down to a rough finish (e.g. relatively coarse smoothing action). Rough-edged blades such as blade  14   a  are generally more effective at shaving unfinished drywall mud than smooth-edged blades, as excess drywall mud is permitted to pass through channels  11 , thereby permitting the leading edge  15   a  to penetrate more deeply into the drywall mud (and/or with relatively less force) than a smooth-edged blade. In some embodiments, blades  14  are arranged so that blade  14   a  leaves behind no more than 1 mm of excess drywall to be shaved by blade  14   b  (and/or other blades, such as blade  14   c ). Rough-edged blades such as blade  14   a  also tend to generate less fine particulate matter than sandpaper. Consequently, relative to smoothing drywall mud with sandpaper, the use of tool  1  to smooth drywall mud may result in the generation of less airborne particulate drywall mud. 
     In some embodiments, blades  14   b  and  14   c  may have leading edges  15   b  and  15   c , respectively, which may be relatively smooth in comparison to leading edge  15   a  of blade  14   a . In some embodiments, blades  14   b  and  14   c  differ; for example, the leading edge  15   b  of blade  14   b  may be rougher than leading edge  15   c  and, optionally, smoother then leading edge  15   a . In some embodiments, blades  14   b  and  14   c  are substantially identical (e.g. blade  14   c  may be substantially identical to blade  14   b  shown in  FIG. 4B ). Smooth-edged blades such as blades  14   b  and  14   c  may be used to provide a smooth finish to partially-finished drywall mud, such as drywall mud initially shaved by blade  14   a . Providing multiple smooth-edged blades  14   b  and  14   c  be convenient in some circumstances, as multiple passes are sometimes desirable to effectively smooth a portion of drywall mud. 
     In some embodiments, corners  13  of blades  14  are rounded for safety, comfort, and/or to reduce the likelihood or severity of blades  14  digging into (and potentially damaging) drywall during use of tool  1 . In some embodiments, blades  14  may be of different lengths (as measured between the leading edge and the opposing edge); for instance, blade  14   a  may have a shorter length than blade  14   b , which may in turn have a shorter length in blade  14   c , thereby allowing blades  14  to collectively provide an interface with drywall mud which is sloped relative to body  2 . Alternatively, or in addition, blades  14  may be set at different locations in blade assembly  10  so that some blades  14  protrude further beyond body  2  than other blades  14 . 
     In some embodiments, one or more of blades  14  may comprise an aperture  19  (shown in dashed lines) through which a rod, screw, or like member may pass to anchor blades  14  to connector  12 . For example, connectors  12  may comprise apertures (not shown) corresponding to apertures  19  and a screw may pass through connectors  12  and blades  14  via the apertures in connectors  12  and blades  14 . For example, the screw (not shown) may be anchored to connector  12   c  and pass through blades  14   a ,  14   b , and  14   c  and connectors  12   a  and  12   b.    
     In some embodiments, blade assembly  10  comprises one or more connectors  12  which connect (i.e. receive, are affixed to, hold in place, and/or otherwise house) blades  14  to blade assembly  10 . Blade assembly  10  may, for example, comprise a single connector which runs along all or part of the width (as measured between transverse edge  17   a ,  17   b , or  17   c  and the opposing transverse edge) of a blade  14 . Blade assembly  10  may, for example, comprise a plurality of connectors which connect blades  14  in a plurality of locations, e.g. transversely spaced-apart locations as illustrated in  FIGS. 1, 2, and 3  by connectors  12   a ,  12   b ,  12   c ,  12   d ,  12   e  (referred to collectively and individually herein as connectors  12 ). 
     Each connector  12  may connect one or more blades  14 . For example, in an embodiment with blades  14   a ,  14   b , and  14   c , one or more connectors  12  may each connect each of blades  14   a ,  14   b , and  14   c  (e.g. as shown in the embodiment of  FIGS. 1, 2, and 3 ). Alternatively, or in addition, one or more connectors  12  may each connect a single blade  12  or a subset of the one or more blades  12 . Connectors  12  may comprise any suitable material, such as rubber, plastic, foam, metal (e.g. aluminum), wood, and/or other materials. 
     In embodiments with a plurality of connectors  12 , connectors  12  may be connected to one another by one or more mounts  16 . For example, mounts  16  may comprise a rod which passes through apertures  18  in connectors  12  (as shown in  FIGS. 2A and 7 ), and/or may comprise a plurality of rods, each affixed to a connector  12  at one or more ends. As another example, mounts  16  may comprise all or a portion of body  2 , in which case connectors  12  may each be connected to body  2  (e.g. as integrally-formed parts of body  2 , or as separately-formed elements engaged with body  2 ). Mounts  16  may be any suitable shape or structure for connecting the connectors  12  of blade assembly  10  to each other. 
     In some embodiments, blades  14  are flexible. Blade assembly  10  may also be flexible and may hold blades  14  to permit flexion of blades  14 . For example, as shown in  FIG. 5A , blades  14  may extend in transverse directions  24  and flex in flexion directions  22 . Blade assembly  10  may provide a plurality of connectors  12  spaced apart in transverse directions  24  and permitting certain connectors  12  (e.g.  12   c ) to move in flexion directions  22  while other connectors  12  (e.g.  12   a ,  12   e ) do not move in flexion directions  22 , move relatively less in flexion directions  22 , and/or move in a direction  22  opposing the movement of the certain connectors  12 .  FIG. 5B  shows an example scenario wherein blades  12  are deformed in flexion direction  22 A away from a support  20  and  FIG. 5C  an example scenario wherein blades  14  are flexed such that at least central portions of blades  14  are deformed in flexion direction  22 B toward support  20 .  FIGS. 5A, 5B, and 5C  are collectively and individually referred to herein as  FIG. 5 . 
     In some embodiments having a plurality of connectors  12 , mounts  16  may be flexible in at least flexion directions  22 . For example, mounts  16  may comprise one or more flexible rods connecting connectors  12 . Thus, flexion of blades  14  may be accompanied by a corresponding displacement of connectors  12  which is matched by flexion in mounts  16 . Mounts  16  may be flexible between two points spaced apart in the transverse directions  24  and substantially fixed in flexion directions  22  at those points. For example, mounts  16  may connect to connectors  12   a  and  12   e , each of which may be attached to body  2  and substantially fixed in flexion directions  22  (as discussed in greater detail below). In embodiments with flexible mounts  16 , mounts  16  may be made of any suitable material, such as flexible plastic, wood, metal, cord, and/or other materials, including non-flexible materials arranged in a flexible structure (e.g. linked chains or the like). 
     In some embodiments, tool  1  comprises an adjustment mechanism  30  for flexing one or more blades  14 . In the embodiment illustrated in  FIG. 5 , adjustment mechanism  30  comprises displacement member  30 . Displacement member  30  is moveable in directions  22  relative to support  20 . Movement of displacement member  30  relative to support  20  may thus change the force experienced by one or more blades  14 , and many correspondingly change the corresponding reaction force experienced by support  20 . Blades  14  may be relatively more deformable than support  20 , and so blades  14  may deform away from support  20  (i.e. in direction  22 A) and/or toward support  20  (i.e. in direction  22 B). In this sense, support  20  may be considered to be an anchor, and movement of displacement member  30  relative to support  20  may increase and/or decrease flexion of one or more blades  14  in direction  22 . 
       FIG. 5B  shows an example scenario where displacement member  30  has been moved in direction  22 A and is pressed against connector  12   c , thereby pushing connector  12   c  away from support  20  and flexing at least a central portion of blades  14  (along with mounts  16  and connectors  12   b ,  12   c , and  12   d ) away from support  20 . Displacement member  30  may be selectively moved to flex blades  14  and/or blade assembly  10  to a greater or lesser degree (e.g. by advancing or retracting displacement member  30 ). 
     In some embodiments, a plurality of adjustment mechanisms  30  (e.g. displacement members  30 ) are provided, thereby providing a user with more options in the flexion of blades  14 . For example, displacement members  30  may be positioned at suitable locations to apply force in directions  22  to connectors  12   a ,  12   c , and  12   e  (and/or at other locations, including at other connectors  12  and other transverse locations relative to blades  14 ), allowing a user to provide different curvatures to different portions of blades  14 . In some such embodiments, connectors  12   a  and  12   e  are permitted to move and/or deform in flexion directions  22  to accommodate the plurality of displacement members  30 . 
     In the illustrated embodiment, displacement member  30  and support  20  are threaded to facilitate the movement of displacement member  30  relative to support  20  in directions  22  by suitable threaded rotation of displacement member  30 . For example, displacement member  30  may be threadably engaged with support  20  via a threaded aperture  32  in support  20 . For example, displacement member  30  may comprise a threaded screw with a head operable to be engaged by a screwdriver, a user&#39;s fingers, or other means for driving a displacement member  30 . 
     Adjustment mechanism  30  (e.g. displacement member  30 ) may comprise any suitable means for flexing one or more blades  14  and/or blade assembly  10  in directions  22  relative to support  20 . For example, adjustment mechanism  30  may comprise a telescoping rod, piezoelectric stack, ratcheted jack, and/or any other adjustable mechanism for displacing a portion of (and thereby flexing) one or more blades  14 . 
     In some embodiments, tool  1  comprises a biasing mechanism  34  for flexing blades  14 . Biasing mechanism  34  biases one or more blades  14  in flexion direction  22 . For example, biasing mechanism  34  may bias one or more blades  14  in direction  22 B towards support  20 , so that (absent a countervailing force from adjustment mechanism  30 ) one or more blades  14  flex in direction  22 B towards support  20 . Thus, biasing mechanism  34  and adjustment mechanism  30  may cooperate to permit flexion both toward and away from support  20  (i.e. in directions  22 A,  22 B), according to the operation of adjustment mechanism  30 . For example, biasing mechanism  34  may flex one or more blades  14  towards displacement member  30  so that retracting displacement member  30  (e.g. moving displacement member  30  in direction  22 B) permits further flexion by biasing mechanism  34  in direction  22 B towards support  20 . Displacement member  30  may overcome the biasing force of biasing mechanism  34  by moving in direction  22 A. 
     An example of a biasing mechanism  34  is shown in  FIG. 5 . In the embodiment shown in  FIG. 5 , biasing mechanism  34  comprises a rod  38  passing through support  20  and connecting at an end to a connector  12  (and in particular, in this example, to one of connectors  12   b  and  12   d ). Biasing mechanism  34  has a head  39  at an opposing end. A spring  36  is provided around rod  38  and bears on support  20  and head  39  to bias head  39  away from support  20  in direction  22 B. Head  39  has a circumference greater than spring  36 , and may comprise a disk, ball, cross, or other suitable shape for retaining spring  36 . When head  39  is biased in direction  22 B away from support  20 , rod  38  connected to connector  12  pulls connector  12  and a corresponding portion of blade  14  in direction  22 B toward support  20 . In this manner, biasing mechanism  34  acts to bias corresponding portions of one or more blades  14  (and/or blade assembly  10 ) in direction  22 B towards support  20 . 
     In the depicted embodiment, two biasing mechanisms  34  are provided, connecting to connectors  12   b  and  12   d  at corresponding transversely spaced apart locations and corresponding transversely spaced apart portions of blades  14  and/or blade assembly  10 . In the illustrated embodiment, each of these locations is located transversely outwardly from the location of adjustment mechanism  30 . In some embodiments, a greater or lesser number of biasing mechanisms  34  are provided, and/or biasing mechanisms  34  may be provided in different locations. For example, a biasing mechanism  34  may be provided at the same location in transverse directions  24  as adjustment mechanism  30  (e.g. appearing to be behind or in front of adjustment mechanism  30  in the  FIG. 5  view) and connect to connector  12   c.    
     Biasing mechanism(s)  34  may also, or alternatively, be provided on an opposing side of blade assembly  10 . For example, a biasing mechanism  34  may be provided at a side of connector  12   c  opposing adjustment mechanism  30  and thus bias connector  12   c  in direction  22 B towards adjustment mechanism  30  and/or support  20 . Such a biasing mechanism  34  may, for example, comprise a spring mounted to body  2  and/or to a second support (not shown) parallel to support  20 . Such biasing mechanisms  34  may alternatively, or additionally, be provided at other locations, such as at the locations of connectors  12   b ,  12   d  and/or other locations on blades  14  directly. 
     Biasing mechanism  34  may comprise any suitable means for flexing blades  14  and/or blade assembly  10  (and/or a corresponding portion thereof) in direction  22 B towards support  20  by biasing all or part of blade assembly  10  and/or blades  14 . For example, biasing mechanism  34  may comprise a spring, an elastic connector between blade assembly  10  and support  20 , and/or any other mechanism for biasing and thereby flexing blade assembly  10  and/or blades  14  and/or corresponding portions thereof. 
     In some embodiments, adjustment mechanism  30  is operable to flex blades  14  (and/or a corresponding portion thereof) in direction  22 B towards support  20  without, or in addition to, the biasing action of biasing mechanism  34 . For example, adjustment mechanism  30  may be affixed to connector  12   c  so that, as adjustment mechanism  30  is retracted in direction  22 B towards support  20 , connector  12   c  is drawn in direction  22 B towards support  20 , thereby causing a corresponding flexion in blades  14  (and/or a corresponding portion thereof) in direction  22 B towards support  20 . In other embodiments, displacement member is not affixed to connector  12   c , e.g. to allow blades  14  to flex further in direction  22 A during use of tool  1 . 
     As blades  14  flex in direction  22 , the total dimension of blades  14  in transverse directions  24  will variously expand and contract. In some embodiments, connectors  12   a  and  12   e  move in transverse directions  24  so as to be positioned closer together as the flexion of blades  14  increases and further apart as the flexion of blades  14  decreases. For example, connectors  12   a  and  12   e  may be movably mounted to body  2  so that connectors  12   a  and  12   e  may move in transverse directions  24  as blades  14  flex, while (optionally) keeping connectors  12   a  and  12   e  substantially fixed in the flexion direction  22 . In some embodiments, one or more connectors  12  may be deformable, and in particular may be deformed in a manner corresponding to the deformation of one or more blades  14 . 
     For example, as shown in  FIG. 1C , one or both of connectors  12   a  and  12   e  may comprise a protrusion  52  which is received in a corresponding aperture or recess of body  2 , such as aperture  50 . Aperture  50  may be elongated in transverse directions  24  and have a width in flexion directions  22  substantially corresponding to a width of protrusion  52 . Thus, protrusion  52  may slide transversely into or out of aperture  50  in transverse directions  24  while remaining substantially fixed in flexion directions  22 . 
     Body  2 , blade assembly  10 , blades  14  and various other elements described above may be used in a variety of drywall mud-smoothing tools, ranging from small handheld tools to large industrial or machine-mounted tools. The present disclosure presents an exemplary handheld tool  1 , described in greater detail below, but it will be understood that the present disclosure is not limited to the illustrated tool  1 . 
       FIGS. 1-3 and 5-7  depict a tool  1  having a body  2  connected to a handle assembly  40 . Handle assembly  40  receives and/or comprises a handle  46  (an example of which is shown in  FIG. 1 ) to be held by a user during use of tool  1 . In the depicted embodiment, handle assembly  40  comprises a body defining an aperture  48 . Aperture  48  may, for example, be threaded and suitable for receiving a threaded end of handle  46 . In some embodiments, handle  46  and handle assembly  40  are integrally formed, so that handle assembly  40  is shaped to be held by a user&#39;s hand. In some embodiments, handle assembly  40  is operable as a handle (e.g. handle assembly  40  may be shaped to be held by a user&#39;s hand) and also provides an aperture  48  for receiving a handle  46 ; thus, for example, handle assembly  40  may be used as a handle when a longer handle is not needed, and a longer handle  46  (e.g. a pole) may be used when needed or desired. 
     Handle assembly  40  may connect to body  2  via one or more support arms  42 . For example, support arms  42  may extend from handle assembly  40  to frame  6  (see  FIG. 1 ). Support arms  42  may connect to body  2  at one or more transverse locations on body  2  and/or continuously across a transverse dimension of body  2  to distribute force applied at handle  46  across body  2 , thereby allowing force applied to handle assembly  40  to distribute transversely across blades  14 . In the embodiment depicted in  FIG. 1 , two support arms  42  are provided which connect with body  2  at a plurality of transversely spaced-apart locations. In some embodiments, one or more wedge-shaped support arms  42  are provided, each support arm widening from a narrow transverse width at handle assembly  40  to a wider transverse width at body  2 , thereby distributing force across body  2 . 
     In some embodiments, handle assembly  40  is pivotably connected to body  2 . For the sake of convenience, body  2  will be referred to as being pivotable relative to handle assembly  40 , although it will be understood that handle assembly  40  can be equivalently understood to pivotable relative to body  2 . Body  2  may pivot in any of several directions. For example, body  2  may pivot about a transverse axis parallel to transverse directions  24  (e.g. so that, as body  2  pivots, leading edges of blades  14  move in roughly flexion direction  22 ).  FIGS. 1-3  depict an example embodiment with this type of pivoting, as discussed further below. Body  2  may also, or alternatively, pivot about an axis parallel to flexion direction  22 . For example, handle assembly  40  may connect to body  2  via a swivel joint, about which body  2  may pivot. 
     In the example embodiment of  FIGS. 1-3 , support arms  42  comprise transversely-oriented axles  60  (i.e. axles oriented parallel to directions  24 ) received by apertures  62  in body  2 . Body  2  may be pivotable about axles  60 , and in particular may be pivotable about an axis  64  extending substantially in transverse directions  24  between axles  60 . 
     A biasing mechanism  44  may be provided between handle assembly  40  and body  2  to bias body  2  towards a particular position relative to handle assembly  40  (e.g. away from handle assembly  40 ). Providing such a bias may help maintain a suitable angle between blades  14  and drywall mud during use of tool  1  while still permitting some flexibility in the position of body  2  relative to handle  46 , which may be desirable in certain circumstances. For example, if tool  1  is being drawn across a particularly uneven portion of drywall mud, biasing mechanism  44  may, in some circumstances, assist in enabling blades  14  to travel in a less-uneven path than would be followed if body  2  were rigidly attached to handle assembly  40 . 
     Biasing mechanism  44  may bias body  2  so that the angle θ at which blades  14  extend relative to handle assembly  40  and/or handle  46  (see, e.g.,  FIG. 3 ) is kept within a range under typical usage conditions and/or at rest. In some embodiments, biasing mechanism  44  may bias body  2  to maintain angle θ in the range of 20° to 60°. For example, biasing mechanism  44  may bias body  2  towards a position where angle θ is 22.5°. Referring to  FIG. 7 , such an angle may enable guides  56  to make contact with drywall  110  while still permitting a separation between drywall  110  and blades  14 . It will be understood that, in some embodiments, certain exertions of force and/or extreme conditions may cause angle θ to leave the range promoted by biasing mechanism  44  temporarily. 
     Biasing mechanism  44  may comprise any suitable means for biasing body  2  towards a particular position or range of positions relative to handle assembly  40 . For example, biasing mechanism  44  may comprise a spring, a resilient connector between handle assembly  40  and body  2 , and/or any other mechanism for biasing body  2  relative to handle assembly  40 . 
     In some embodiments, tool  1  provides a guide  56  for guiding body  2  along drywall during use. Guide  56  may assist in maintaining registration between leading edges  15  and a portion of drywall mud during use of tool  1 , may space body  2  away from the drywall and/or drywall mud during use of tool  1 , and/or may assist the user in smoothly moving body  2  along the drywall and/or drywall mud. Tool  1  may comprise any number of guides  56 , but in some embodiments tool  1  comprises at least two guides  56 —a first guide  56  proximate to one transverse side of body  2  and a second guide  56  proximate to an opposing transverse side of guide  56 . The guides  56  may be spaced apart sufficiently in transverse directions  24  (e.g. 15 cm to 60 inches, or 6 inches to 24 inches, in various embodiments) to allow a typical expanse of drywall mud to fit between them; in such embodiments, guides  56  may be adapted to smoothly slide, roll, or otherwise move along drywall while blades  14  smooth the drywall mud applied to the drywall between the guides  56 . 
     In some embodiments, the position of guide  56  is adjustable in protrusion directions  26  (shown in  FIG. 3 ) relative to body  2  and/or blades  14 . A user may adjust such guides  56  to protrude past leading edges  15  in protrusion direction  26 , retract behind leading edges  15  of blades  14  in protrusion direction  26 , and/or remain flush with leading edges  15  in protrusion direction  26 . Different degrees of adjustment may be desirable depending, for example, on the depth that the user desires blades  14  to shave drywall mud. Retraction of guide  56  may cause body  2  to be positioned closer to the drywall, thereby assisting blades  14  in penetrating deeper (and thereby shaving deeper) into the drywall mud during use. 
     In one non-limiting example embodiment, guide  56  may comprise a wheel mounted to frame  6 . Guide  56  may protrude beyond body  2  in protrusion direction  26 B so that, when leading edges  15  are each positioned against a portion of drywall mud (such as drywall mud  100  applied to drywall  110  in  FIG. 6 ), guide  56  is suitably positioned to support body  2  against the drywall and/or drywall mud. An example of such an arrangement is shown in  FIG. 6 . 
     Guide  56  may comprise a wheel, a flat surface (e.g. defined by body  2 ) for sliding along a portion of drywall, and/or any other suitable structure which assists with maintaining registration between leading edges  15  and drywall mud during use of tool  1 . 
     In some embodiments, the position of one or more blades  14  is adjustable in protrusion directions  26 . For example, one or more adjustment mechanisms (such as displacement member  30 ) may be anchored to body  2  and extend towards blade assembly  10  in protrusion direction  26 B. Moving these adjustment mechanisms (not shown) in protrusion direction  26 B may cause blades  14  to protrude further beyond guide  56 , thereby allowing relatively deeper shaving of drywall mud, substantially as discussed above. Moving these adjustment mechanisms (not shown) in protrusion direction  26 A may cause blades  14  to protrude less far beyond guide  56 , and/or even retract behind guide  56  in protrusion direction  26 A, thereby allowing relatively shallower shaving of drywall mud. In some embodiments, one or more blades  14  are selectively adjustable in protrusion directions  26  independently of one or more other blades  14 ; for example, rough-edged blade  14   a  may be advanced so that leading edge  15   a  protrudes beyond leading edges  15   b  and/or  15   c  in protrusion direction  26 B. 
       FIGS. 6 and 7  illustrate a method for smoothing dried drywall mud according to the present disclosure. Tool  1  may be positioned against drywall  110  so that the one or more blades  14  abut drywall mud  100 . Tool  1  may then be advanced along drywall  110  in advancement direction  120  (e.g. by a user applying force to handle  46 ). The user applies force to handle  46 , which causes blades  14  to pass across a portion of drywall mud  100  with sufficient force to at least partially smooth drywall mud  100 . Each successive pass of a blade  14  across a portion of drywall mud  100  may further smooth the portion of drywall mud  100 . 
     In embodiments with multiple blades  14 , this process may be expedited. For example, a rough-edged blade  14   a  may advance along an unfinished drywall mud portion  102 , thereby shaving excess drywall mud and transforming unfinished drywall mud portion  102  into rough drywall mud portion  104 . Rough-edged blade  14   a  may comprise one or more channels  11  through which excess drywall mud may pass as unfinished drywall mud portion  102  is shaved. As tool  1  is drawn across drywall  110 , smooth-edged blade  14   b  may be subsequently drawn across rough drywall mud portion  104 , thereby further smoothing portion  104 . Additional blades, such as smooth-edged blade  14   c , maybe be subsequently drawn across rough drywall mud portion  104 , thereby smoothing portion  104  even further. Such smoothing may transform rough drywall mud portion  104  to a relatively smoothed drywall mud portion  106 . Thus, a plurality of adjacent unfinished drywall mud portions  102  may be smoothed into relatively smoothed drywall mud portions  106  by simultaneously advancing the several blades  14  along portions of drywall mud  100 . 
     In some embodiments, blades  14  may be flexed to permit the smoothed portion  106  to possess some curvature. For example, when smoothing drywall mud on top of a tape seam, the corner, counter-sunk screw, and/or the like, it may be desirable for the drywall mud to have increased thickness in that location (while still appearing smooth) to conceal the underlying feature, whereas it may be desirable for drywall mud away from the feature to be concealed to have decreased thickness to blend with the surrounding drywall  100 . In some circumstances, this may be accomplished by flexing blades  14  in the appropriate direction prior to smoothing drywall mud  100 . As another example, it may be desirable to provide a particular curvature to drywall mud  100  when smoothing a curved portion of drywall  110 . 
     As discussed above, flexion may be accomplished by adjusting adjustment mechanism  30  (e.g. displacement member  30 ) to press against blade assembly  10  and/or blades  14 , thereby selectively flexing corresponding portions of blades  14 . Alternatively, or in addition, blades  14  may be flexed by a biasing mechanism  34  (optionally mediated to a countervailing force exerted by an adjustment mechanism  30 ). Once flexed, the one or more blades  14  may be positioned against a portion of drywall mud  100  and advanced along the drywall mud to engage in a smoothing action substantially as described above. 
       FIGS. 8-10, 11A and 11B  (collectively and individually “ FIG. 11 ”), and  12 A and  12 B (collectively and individually “ FIG. 12 ”) show another example drywalling tool  200 . Throughout  FIGS. 8-12 , like reference numerals refer to like features of  FIGS. 1-7 ; for example, blade assembly  210  corresponds generally to blade assembly  10 , although like-numbered features may comprise various differences as described in greater detail herein. For convenience, drywall tool  200  is generally described with reference to the same directions  22 ,  24 ,  26  as were provided in  FIGS. 1-7 . 
     Drywall tool  200  comprises a body  202  coupled to a frame  206 . Body  202  may be shaped to be held by a user (and thus may function as a handle). A blade assembly  210  is coupled to frame  206  and retains one or more blades  14  having leading edges  15 . Blade assembly  210  comprises one or more connectors  212  for retaining blades  14  and, in some embodiments, one or more biasing mechanisms  234  for flexing blades  14 . In the depicted embodiment, blade assembly  210  retains one blade  14 , although it will be appreciated that blade assembly  210  may retain a plurality of blades  14  (e.g. as described above). 
     Biasing mechanisms  234  bias one or more blades  14  in flexion direction  22 . In some embodiments (including the depicted embodiment of  FIGS. 8-12 ), biasing mechanisms  234  bias blade  14  in flexion direction  22 A toward body  202 . In some embodiments, biasing mechanisms  234  do not flex blade  14  when at rest; that is, when blade  14  is substantially unflexed (and is not being flexed in flexion direction  22 B by a countervailing force), biasing mechanisms  234  do not exert any significant force on blade  14  in direction  22 A. 
     In some embodiments (including the depicted embodiment of  FIGS. 8-12 ), adjustment mechanism  30  is omitted, and biasing mechanisms  234  provide tension which partially counteracts flexion of blade  14  in flexion direction  22 B caused by (for example) drywall mud being smoothed by blade  14 . By maintaining such tension, biasing mechanisms  234  may enable blade  14  to more effectively smooth drywall mud (relative to an unbiased blade which flexes away from such drywall mud more easily) while still providing some flexibility of blade  14  in flexion directions  22 . 
     Biasing mechanisms  234  may be of any suitable construction, as described above. In some embodiments, biasing mechanisms  234  comprise rods  238 , springs  236 , and (optionally) heads  239 . Such biasing mechanisms  234  are best shown in  FIGS. 9 and 10 .  FIG. 9  is a side elevation view of drywalling tool  200 , and  FIG. 10  is a cross-sectional view of drywalling tool  200  taken along line B-B of  FIG. 9 . In some embodiments, rods  238  connect to blade assembly  210  (e.g. to connectors  212 ) and heads  239  are retained in cavities  219  of body  202 . Springs  236  may be retained between connectors  212  and an internal surface of cavity  219 , thereby biasing body  202  and connectors  212  against each other. Springs  236  may be further retained by rods  238 . 
     In some embodiments, head  239  abuts an internal surface of cavity  219  when body  202  is moved close to connectors  212 , thereby preventing body  202  from moving nearer to connectors  212 . In some embodiments, head  239  is retained in cavity  219  so that, when body  202  is moved away from connectors  212 , head  239  prevent at least a portion of body  202  from moving beyond head  239 , thereby preventing body  202  from moving further away from connectors  212 . For example, head  239  may abut against a support  220  of body  202 . Head  239  does not necessarily retain spring  239  in such embodiments, as that function may be provided by body  202  and/or other elements of drywalling tool  200 . 
     In the depicted embodiment, thirteen biasing mechanisms  234  are provided, connecting to a corresponding number of connectors  212 . Any suitable number of biasing mechanisms  234  may be provided. In some embodiments, a sufficient number of biasing mechanisms  234  are provided so that each biasing mechanism  234  is spaced apart from adjacent biasing mechanisms  234  by at most 2.5 cm (approximately 1 inch). In some embodiments, some biasing mechanisms  234  provide less biasing force than other biasing mechanisms  234 . For example (and as shown in the depicted embodiment), transversely outermost biasing mechanisms  234   b  provide greater biasing force (e.g. by providing springs  236  with a greater spring constant) than transversely inward biasing mechanisms  234   a.    
     Transversely inward biasing mechanisms  234   a  may connect to transversely inward connectors  212   a  and transversely outermost biasing mechanisms  234   b  may connect to transversely outermost connectors  212   b . In some embodiments, transversely outermost biasing mechanisms  234   b  retain blade  14  relatively more securely than transversely inward biasing mechanisms  234   a . For example, transversely outermost biasing mechanisms  234   b  may prevent the portions of blade  14  which they retain from bending (e.g. to prevent the edges of blade  14  from gouging drywall during use). In some embodiments, transversely outermost biasing mechanisms  234   b  are fixedly attached to frame  206  (e.g. by fasteners  208 ). In some embodiments, transversely outermost biasing mechanisms  234   b  are longer in transverse directions  24  than transversely inward biasing mechanisms  234   a.    
     In some embodiments, connectors  212  may be connected to one another by one or more mounts  216 . For example, mounts  216  may comprise a rod which passes through apertures  218  in connectors  212 , and/or may comprise a plurality of rods, each affixed to a connector  212  at one or more ends. Alternatively, or in addition, mounts  216  may be otherwise constructed, as described above. Mounts  216  may be any suitable shape or structure for connecting the connectors  12  of blade assembly  10  to each other. 
     In some embodiments, body  202  is pivotably connected to frame  206 . For example (as shown in the depicted embodiment), body  202  may be connected to frame  206  by a hinge  260 . Body  202  may pivot about hinge  260 . Biasing mechanisms  234  may bias such pivoting movement so that pivoting toward connectors  212  is typically opposed and pivoting away from connectors  212  is amplified by biasing mechanisms  234  (although it will be understood that, if body  202  is pulled away from connectors  212  beyond a neutral position of biasing mechanisms  234 , this opposition/amplification relationship may be reversed). Such opposition and/or amplification may be overcome by the application of force against body  202  by a user. 
     In some embodiments, drywalling tool  200  provides a guide  256 . As described above with reference to guide  56 , guide may comprise a wheel mounted to frame  206 , a flat surface (e.g. defined by frame  206 , body  202 , and/or blade assembly  210 ) for sliding along a portion of drywall, and/or any other suitable structure which assists with maintaining registration between leading edges  15  and drywall mud during use of tool  200 . In at least the depicted embodiment, an outermost edge of guide  256  is substantially parallel with leading edge  15  in flexion direction  22 . 
       FIGS. 11 and 12  show additional views of drywalling tool  200 , for greater clarity.  FIG. 11A  shows a front elevation view of drywalling tool  200 , whereas  FIG. 11B  shows a back elevation view (i.e. from an opposing side to the view of  FIG. 11A ) of drywalling tool  200 .  FIGS. 12A and 12B  show plan views of opposing sides of drywalling tool  200 ; for convenience,  FIG. 12A  may be considered to provide a “top” view, and  FIG. 12B  may be considered to provide a “bottom” view (although, as described below, “top” and “bottom” do not limit the orientations of drywalling tool  200 ). 
     As shown (for example) in  FIGS. 11B and 12B , in some embodiments one or more connectors  212  may be fastened to blade  14  by fasteners  208 . For example, transversely outermost connectors  212   b  may comprise fasteners  208  to fasten blade  14  thereto. One or more transversely inward connectors  212   a  may also, or alternatively, be fastened to blade  14  by one or more fasteners  208 . In at least the depicted embodiment, blade  14  is fastened to connectors  212  at at least three locations—two transversely outward locations and one transversely central location. Fastener  208  may comprise, for example, a screw, post, clamp, and/or other fastening mechanism. 
     Drywalling tool  200  may be used substantially similarly to drywalling tool  1 —namely, drywalling tool  200  may be applied against drywalling mud (e.g. drywalling mud  100 ) and advanced along such drywalling mud to smooth it. In operation, a user applies force to body  202  to move drywalling tool  200  in an advancement direction (e.g. advancement direction  120 ). This force causes blade  14  to pass across a portion of drywall mud with sufficient force to at least partially smooth said drywall mud. 
     In some embodiments, including the depicted embodiment, a user may apply force against body  200  in flexion directions  22 , thereby causing pivoting movement of body  202  relative to blade  14 . Such movement may cause flexion of blade  14  in flexion direction  22 A. However, in circumstances where drywalling mud is applying force against blade  14  so as to cause flexion in flexion direction  22 B, force applied by a user in flexion direction  22 A may counteract the force of the drywalling mud and thus may serve to reduce the flexion of blade  14  (and increase the force exerted by blade  14  against the drywalling mud). A user may selectively increase or decrease the force applied against blades  14  by correspondingly increasing or decreasing the force applied against body  202  in flexion direction  22 A (without necessarily adjusting the force exerted in the advancement direction). 
     INTERPRETATION OF TERMS 
     Unless the context clearly requires otherwise, throughout the description and the claims:
         “comprise”, “comprising”, and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”;   “connected”, “coupled”, or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof; elements which are integrally formed may be considered to be connected or coupled;   “herein”, “above”, “below”, and words of similar import, when used to describe this specification, shall refer to this specification as a whole, and not to any particular portions of this specification;   “or”, in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list;   the plural forms “blades”, “mounts”, and “directions” are used at various points in place of the term “one or more blades”, “one or more mounts”, and “one or both directions”, respectively, and accordingly include the meaning of the singular forms “blade”, “mount”, and “direction”, respectively (and vice-versa);   the singular forms “a”, “an”, and “the” also include the meaning of any appropriate plural forms.       

     Words that indicate directions such as “vertical”, “transverse”, “horizontal”, “upward”, “downward”, “forward”, “backward”, “inward”, “outward”, “vertical”, “transverse”, “left”, “right”, “front”, “back”, “top”, “bottom”, “below”, “above”, “under”, and the like, used in this description and any accompanying claims (where present), depend on the specific orientation of the apparatus described and illustrated. The subject matter described herein may assume various alternative orientations. Accordingly, these directional terms are not strictly defined and should not be interpreted narrowly. 
     Specific examples of systems, methods and apparatus have been described herein for purposes of illustration. These are only examples. The technology provided herein can be applied to systems other than the example systems described above. Many alterations, modifications, additions, omissions, and permutations are possible within the practice of this invention. This invention includes variations on described embodiments that would be apparent to the skilled addressee, including variations obtained by: replacing features, elements and/or acts with equivalent features, elements and/or acts; mixing and matching of features, elements and/or acts from different embodiments; combining features, elements and/or acts from embodiments as described herein with features, elements and/or acts of other technology; and/or omitting combining features, elements and/or acts from described embodiments. 
     It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions, omissions, and sub-combinations as may reasonably be inferred. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.