Wipe-down knife

Information

  • Patent Grant
  • 6295689
  • Patent Number
    6,295,689
  • Date Filed
    Wednesday, December 2, 1998
    26 years ago
  • Date Issued
    Tuesday, October 2, 2001
    23 years ago
Abstract
The wipe-down knife herein is assembled upon an elongate handle, one end of which is fitted with a generally cylindrical blade-supporting head. The head has a collar and lever arm on one end for securely engaging the handle shaft, and a pair of closely opposed pads and a pivot pin on its other end for engaging a blade-supporting plate. A bracket which grasps the blade at its base is affixed to the blade-supporting plate. The blade is wide and flexible, projecting from the blade support at a right angle to the longitudinal axis of the knife's handle. The blade curves away from the blade-supporting bracket at a right angle, such that the plane of the blade's working edge is parallel with the handle's longitudinal axis.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates generally to hand tools for smoothing-out pastey and plastic substances on planar surfaces, and more specifically to wipe-down knives for smoothing wet plaster and other finishing compounds during drywall construction.




2. Description of the Related Art




In the phase of residential and commercial building construction in which the interior wall surfaces are applied to supporting studs, sheet rock panels are nailed or screwed to the studs and then the seams therebetween are taped-over and plastered. After tape and plaster are applied to the seams, the surface of each seam must be wiped-down to give it a finished surface appearance and to prepare it for the application of paint.




The wipe-down phase of drywall construction is commonly carried out with the use of a short hand trowel. However, using a hand trowel for wipe-down purposes has many drawbacks. For example, most hand trowels have a relatively short blade which requires the user to make multiple horizontal passes back and forth across the seam to yield a ridge-free seam surface appearance. Further, on walls where the ceiling height is over eight feet, or so, the user must climb upon a ladder, scaffold or other apparatus to reach and wipe-down the seams.




Various long-handled trowels have been proposed, but these are generally clumsy and more difficult to control as their handles get longer. And, despite their long handles, it is difficult to apply the blade of a long-handled trowel to a wall surface at the proper angle to smooth-out plaster.




The apparatus of U.S. Pat. No. 4,817,229 issued to Sedillo in 1989, comprises a swiveling, short-edged, semicircular-shaped trowel blade on a long handle pole for wiping-down high seams. Sedillo's apparatus attempts to address the problem of achieving the correct blade-to-wall angle when using a long-handled trowel, but it is difficult to use and lacks the durability the journeyman drywall specialist would normally expect of his or her tools. Further, Sedillo's short blade makes it necessary to use a great many individual strokes in smoothing out a plaster surface. This makes it difficult to avoid telltale ridges between strokes.




Several long-bladed trowels have been proposed for the purpose of reducing the number of strokes required to finish a plaster surface. However, those constructed of metal are too heavy and not sufficiently flexible because, when thinner sheets of metal are used, these tend to deform upon being bolted as securely as necessary to an elongate blade-supporting bar. Securely bolting a thin metal blade along one edge tends to warp the opposing edge and make it wavy; this results in a wavy pattern in the plaster surface being worked. The same has been found in experimenting with over-sized plastic blades.




Thus, it appears that a need exists for a wipe-down knife fit for use in all drywall seam-finishing operations, no matter the height of the wall being finished.




SUMMARY OF THE INVENTION




The wipe-down knife of the present invention is adapted to overcome the above-noted shortcomings and to fulfill the stated needs. It is assembled upon an elongate handle, one end of which is fitted with a generally cylindrical, blade-supporting head. The head has means on one end for securely engaging the handle shaft and means on its other end for engaging blade-supporting apparatus. The blade support comprises a plate and bracket which grasp the blade at its base. The blade is wide and flexible, projecting from the blade support at a right angle to the longitudinal axis of the knife's handle, and curving roughly 90 degrees such that the plane of its working edge is parallel with the handle's longitudinal axis.




It is an object of the present invention to provide a wipe-down knife that is easier to use than earlier tools in finishing drywall in high-ceilinged rooms.




It is a further object of the present invention to provide a wipe-down knife that is more versatile and durable than earlier tools available to the drywall specialist.




Still a further object of the present invention is to provide a wipe-down knife having interchangeable parts of different sizes, so that the drywaller needing a tool having a shorter or longer handle, or a wider or narrower blade, is able to adapt the tool with an interchangeable part best suited to his or her immediate purpose.




Another object of this invention is to provide a blade-supporting assembly for an over-sized wipe-down knife blade which assures that the working edge remains straight and waveless.




Yet another object of this invention is to provide a long-handled tool with an adjustable, flexible blade suited to many different purposes in a wide array of skills, tasks, industries, professions and arts.











Still further objects of the inventive wipe-down knife disclosed herein will be apparent from the drawings and following detailed description thereof.




BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of the wipe-down knife of the invention.





FIG. 2

is a rear elevational view of the wipe-down knife of the invention, showing its working face and showing the range of motion of its blade in dashed lines.





FIG. 3

is a side elevational view, partially in cross-section, of the inventive wipe-down knife as it is shown in





FIG. 2

, the cross-section being taken on line


3





3


.





FIG. 4

is an enlarged detail view taken from the cross-sectional portion of

FIG. 3

showing the ribs on the non-working surface of the blade.





FIG. 5

is a cross-sectional view of the blade base-grasping bracket, alone.





FIG. 6A

is an exploded, partial, perspective view of the head and blade-mounting plate of the wipe-down knife of the invention.





FIG. 6B

is an exploded, partial, perspective view, continuing from

FIG. 6A

, showing the blade and blade base-grasping bracket of the wipe-down portion of the invention.





FIG. 7

is a side elevational view of the entire head portion of the wipe-down knife of the invention.





FIG. 8

is a front elevational view of the head portion shown in FIG.


7


.





FIG. 9

is a cross-sectional view of the head of

FIG. 7

, taken on line


9





9


thereof.





FIG. 10

is a side elevational view of a first alternative embodiment of the wipe-down knife of the invention, having an angled blade-mounting plate.





FIG. 11

is a front elevational view of an alternative blade-mounting plate having a hinge incorporated therein.





FIG. 12

is an enlarged, fragmentary, partially cross-sectional sectional, side elevational view of the hinged blade-mounting plate of

FIG. 11

incorporated into a second alternative wipe-down knife.





FIG. 13

is a side elevational view of the second alternative wipe-down knife of

FIG. 11

, showing the hinged blade-mounting plate in a flexed posture.











DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring now specifically to the drawings,

FIGS. 1 through 6A

and


6


B show a first embodiment of the inventive wipe-down knife, which is generally identified herein with the reference numeral


10


.




Wipe-down knife


10


is assembled from five primary components: handle shaft


12


; head


14


; blade-mounting plate


16


; blade base-grasping bracket


18


; and, blade


20


.




Handle shaft


12


is preferably fashioned from a straight length of tubular aluminum stock, roughly 1.375 inches in diameter, and 0.035 inch thick. The length of handle shaft


12


will commonly be approximately two feet, or so. However, when a longer reach is required, as when ceilings are higher than about 10 feet, greater lengths of tubular stock may be employed in the construction of handle shaft


12


. Likewise, for jobs in tight spaces or of minimal height, handle shafts one foot, or less, may suffice. It is also contemplated that multiple, interchangeable, different-length handle shafts


12


, each having inside and outside diameters identical to the others may be kept at the ready to meet differing needs as they arise. Each such handle shaft


12


, having inside and outside diameters equal to all others, would mate equally well with head


14


. It is further contemplated that handle shaft


12


may be comprised of a plurality of separate lengths of tubular stock, each being able to be securely bound to the next with a connector or adapter (not shown), many types of which are well known in the art. Such subunits employed to create a handle shaft of custom length may be of equal or unequal length. The terminal end of handle shaft


12


, opposite the end which receives head


14


, may be fitted with any of a variety of known plugs or covers (not shown). Alternative handle shaft constructions comprised of different materials, such as steel or plastic, are also envisioned. Further, a handle shaft having a solid body throughout, but having a hollow end able to receive head


14


, would also likely work satisfactorily.




Head


14


is a unitary structure having an elongate, generally cylindrical shape, with a diameter approximately the same as the outer diameter of handle shaft


12


. Head


14


is shown separately in

FIGS. 7 and 8

.




Head


14


is constructed of durable, molded plastic. A combination of polypropylene mixed with 30-40% glass fiber has been found to yield a sufficiently durable product. However, it is contemplated that head


14


may be made from other rigid substances, such as metal, and some woods.




The rearward portion of head


14


is adapted to engage the open end of handle shaft


12


, and the forward portion is adapted to have blade-mounting plate


16


affixed thereto. These opposed portions or ends of head


14


are identified herein with reference numerals


22


and


24


, respectively. Handle-engaging portion


22


of head


14


comprises roughly two-thirds of head


14


's length and is comprised of two primary components, tapered collar


26


and lever arm


28


.




Tapered collar


26


is a frustoconically-shaped structure, tapered such that its diameter decreases from handle end edge-abutting step


30


toward handle-engaging end


22


of head


14


. Collar


26


's largest diameter is directly adjacent abutting step


30


, where it is preferably the same diameter as, or slightly larger than, the inside diameter of handle shaft


12


. The diameter of collar


26


's smaller end is preferably about 0.003 inch less than collar


26


's larger end. Ultimately, collar


26


should be shaped and dimensioned such that, when inserted into the open end of handle shaft


12


and driven in an axial direction toward the handle's opposite end, collar


26


seats snugly in secure frictional engagement with the inside wall of handle shaft


12


immediately adjacent its end edge. Collar


26


should reach its most secure fit within handle shaft


12


just as the end edge


32


of handle shaft


12


approaches and abuts handle end edge-abutting step


30


. The depth of step


30


, from the uniform diameter of the cylindrical portion of head


14


's blade-mounting portion


24


, to the diameter of the largest portion of collar


26


is approximately 0.035 inch, the same thickness as the tube stock from which handle shaft


12


is fashioned. And, the diameter of blade-mounting portion


24


of head


14


is the same as the outside diameter of handle shaft


12


. Thus, when collar


26


of head


14


is fully seated within the open end of handle shaft


12


, and when handle shaft


12


's end edge


32


abuts step


30


, a relatively unbroken, cylindrical surface of uniform diameter from handle shaft


12


through to blade-mounting portion


24


of head


14


results.




Lever arm


28


of head


14


seats deeper within handle shaft


12


than collar


26


. As shown in

FIGS. 8 and 9

, lever arm


28


is cruciform in cross-section, being comprised of four elongate, equally-dimensioned, generally rectangular components


34


, each rectangular component


34


projecting radially at a right angle to its two most closely adjacent components


34


. Each rectangular component also bears a radially-projecting shoe


36


on its outermost, endmost edge. Each shoe


36


is slightly tapered in a manner which causes a cross-section taken closer to the end of lever arm


28


to have a smaller width than a cross-section taken farther from lever arm


28


's end. Lever arm


28


's maximum width, including shoes


36


, should be the same or slightly less than the inside diameter of handle shaft


12


, such that it slides easily but snugly into handle shaft


12


and seats securely therein.




Head


14


's tapered collar


26


and lever arm


28


cooperate to keep head


14


securely seated within the end of handle shaft


12


. As force is directed in a radial direction against the blade-mounting end


24


of head


14


, as commonly occurs in the normal use of wipe-down knife


10


, collar


26


acts as a fulcrum and lever arm


28


's shoes


36


brace against the opposite portion of inner surface of handle shaft


12


deep within its length.




Head


14


's blade-mounting portion


24


is uniformly cylindrical near step


30


. But, moving forward, blade-mounting portion


24


loses its radial symmetry and flattens out into a pair of identical, projecting, paddle-like pad


38


of a width somewhat greater than the diameter of the rest of head


14


. Pads


38


are of equal thickness; and, they are parallel and closely opposed to one another, such that a deep, planar slot


40


of uniform width is defined therebetween. Slot


40


is parallel to head


14


's longitudinal axis. The depth of slot


40


is preferably such that its bottom edge


42


resides at about the point where the cross-section of head


14


's blade-mounting portion transforms from a circular toward a flattened shape.




Each flattened pad


38


includes a centrally-placed, transverse aperture


44


. Apertures


44


are aligned with one another such that a pivot pin


46


may be passed therethrough to span slot


40


in a direction perpendicular to head


14


's longitudinal axis. Pivot pin


46


must include some means for drawing pads


38


toward one another, thus narrowing slot


40


, and for fixing pads


38


in place in their movement toward one another. Thus, pivot pin


46


may conveniently be a common fastener such as a machine screw, or the like, employed with cooperating, domed, compression washer


48


(also sometimes referred to as a button washer) ; flat washer


50


; and, hex nut


52


. This is shown in FIG.


6


A. The length of pivot pin


46


should be sufficient to permit it to pass through both adjacent pads


38


as well as to permit a portion of its threaded end to project beyond the outer face of the pad


38


opposite that where the head of pivot pin


46


is seated. As the machine screw of pivot pin


46


is tightened, compression washer


48


tends to exert back-pressure against the screw's head and against flat washer


50


, thus tending to hold the machine screw in position and keep it from loosening during use. Thus, compression washer


48


serves a tension-retaining function in the operation of pivot pin


46


.




For convenience in tightening pivot pin


46


, one pad


38


may include boss


54


surrounding its aperture


44


, wherein boss


54


includes a hex-shaped cutout


56


for receiving and retaining hex nut


52


. This is best viewed in

FIGS. 7 and 8

.




Slot


40


receives planar, T-shaped, rigid blade-mounting plate


16


. Blade-mounting plate


16


is constructed from rigid metal stock, preferably aluminum, having a thickness which permits plate


16


to be slidingly received in slot


40


with slight friction from the inner surfaces of both flattened pads


38


. Blade-mounting plate


16


's central lobe


58


includes pivot pin aperture


60


. Aperture


60


is preferably located deep enough within the planar surface of blade-mounting plate


16


, i.e. as far as possible from its outer edges, such that a substantial amount of surface area surrounds aperture


60


on all sides. This is to assure that, when blade-mounting plate


16


is assembled with head


14


by passing pivot pin


46


through apertures


44


and aperture


60


as shown in

FIG. 6A

, there is sufficient surface area of the inner faces of pads


38


in contact with the surfaces of blade-mounting plate


16


to permit plate


16


to be securely grasped by pads


38


and held in any desired position.




The force with which pads


38


impinge upon blade-mounting plate


16


is adjustable by turning the screw head of pivot pin


46


. As desired, pads


38


may be drawn tightly toward one another to grasp plate


16


very firmly, or they may be loosened to permit plate


16


to pivot freely side-to-side in slot


40


. However, ideally, pivot pin


46


should be tightened to a point which permits plate


16


to retain a fixed position under normal working conditions, but which permits the position of plate


16


in slot


40


to be changed at will by the user, without the need to resort to turning the screw head or otherwise adjusting the tension with which pivot pin


46


draws pads


38


toward one another. Thus, pads


38


and pivot pin


46


of head


14


's blade-mounting end


24


cooperate to function as an adjustable yoke, fixing blade-mounting plate


16


inextricably in slot


40


such that plate


16


is rotatable through a wide, planar arc, yet permitting plate


16


's position to be fixed at any desired point throughout that arc.




Blade base-grasping bracket


18


is an elongate structure oriented transverse to the longitudinal axis of wipe-down knife


10


, as established by handle shaft


12


. That is, bracket


18


's own longitudinal axis is perpendicular to the longitudinal axis of handle shaft


12


. Bracket


18


has a generally L-shaped cross-section adapted to engage the base of blade


20


and to cooperate with blade-mounting plate


16


as a blade support structure. Bracket


18


is comprised of a first planar panel


62


projecting in a first plane perpendicular to bracket


18


's longitudinal axis, and a second planar panel


64


, integral with first panel


62


at a common apex


66


, projecting in a second plane perpendicular to bracket


18


's longitudinal axis. The second plane in which second planar panel


64


resides is also generally perpendicular to the plane in which first panel


62


resides. First and second panels


62


and


64


are preferably integral with one another; i.e., bracket


18


is preferably a unitary structure.




Closer examination of bracket


18


reveals that second panel


64


projects farther from apex


66


than first panel


62


, and that second panel


64


is folded back upon itself toward the interior angle


68


of apex


66


. The folded-back portion


70


of the farther-projecting second panel


64


is parallel to, but spaced apart from, the primary, base portion


72


of second panel


64


which is closer to apex


66


. Thus, a slot-shaped space


73


is defined between the folded-back portion


70


of second panel


64


and the primary, base portion


72


thereof. However, the terminal end edge


74


of folded-back portion


70


falls short of abutting first panel


62


, thus leaving the opening necessary for nesting the base of blade


20


within bracket


18


.




Satisfactory results have been achieved from a bracket


18


constructed of polycarbonate plastic, although now-known or later-discovered materials may work as well or better in performing the function of this element of the invention.




Blade


20


is constructed from a substantially rectangular sheet of polycarbonate plastic approximately 0.070 inch thick. Once molded into its permanent working form, blade


20


's shape is best described from the viewpoint of looking at its side edge, as in

FIG. 3

, as it is from this view that the majority of blade


20


's salient features may be viewed. This is adequate, as all surfaces of blade


20


have a straight axis which is substantially parallel to the length of blade base-grasping bracket


18


.




Overall, blade


20


has a generally L-shaped cross-section. Blade


20


has an anchor tab


76


at its base which is received securely within the slot-shaped space


73


between the folded-back portion


70


and the primary, base portion


72


, of second panel


64


. A right-angled nesting portion


78


of blade


20


directly adjacent to anchor tab


78


is adapted to seat nestingly against interior angle


68


of blade base-grasping bracket


18


's apex


66


. Immediately adjacent to nesting portion


78


, and farther from anchor tab


78


, blade


20


has a curved hinge portion


80


. Curved hinge


80


comprises an arced bend of approximately 90 degrees. The working edge portion


82


of blade


20


projects straight away from curved hinge


80


, and extends therebeyond for several inches.




Blade


20


has a working face


84


and a non-working face


86


. Working face


84


of blade


20


is that face intended and adapted to be pressed against a wall surface in the use of wipe-down knife


10


. Working face


84


is contiguous with the outer surface of the arc of curved hinge


80


. Non-working face


86


is the surface of blade


20


opposed to working face


84


, i.e. the face contiguous with the inner surface of the arc of curved hinge


80


. Working face


84


is smooth-surfaced. In contrast, a plurality of closely-spaced ridges


88


cover substantially the entirety of non-working face


86


. Ridges


88


are shown in the enlargement of FIG.


4


. The portion of non-working face


86


covered with ridges


88


is identified with the bracket numbered


89


in FIG.


3


. Ridges


88


do not cover any portion of the inside or outside arcs of curved hinge


80


. Ridges


88


are parallel to working edge


82


; they serve to make the planar portion of blade


20


stiffer than the more flexible, non-ridged, curved hinge portion


80


. This combination of flexible and less-flexible portions in blade


20


is preferred to achieve the optimum comfortable workability of wipe-down knife


10


.




Blade


20


and blade base-grasping bracket


18


are affixed to blade-mounting plate


16


with several blade-fastening screws


90


. This is shown in

FIGS. 1

,


3


,


6


A and


6


B. Blade-fastening screws


90


pass through blade-fastening apertures


92


in blade-mounting plate


16


. Cooperating apertures


94


in blade base-grasping bracket


18


, and apertures


96


in anchor tab


76


at the base of blade


20


, register with apertures


92


in plate


16


. Screws


90


are held securely in place through apertures


92


,


94


and


96


with button washers


98


at the head-ends of screws


90


and, at their opposed, threaded ends, with nylon-lined, locking hex nuts


100


. Locking nuts of the type sold under the Nylock brand name work satisfactorily for this purpose.




The preferred material for construction of blade


20


is polycarbonate plastic. However, other now-known or later-discovered materials may work satisfactorily in construction of blade


20


. For example, a thin, spring steel blade may work better than normally expected when incorporated into the apparatus disclosed herein.




It is also contemplated that blades of different sizes constructed in accordance with the foregoing disclosure may be employed for different purposes. Wider blades, and blades with greater distances between their anchor tabs


76


and working edges


82


, may all have specific uses. And, a number of these may be kept handy as interchangeable parts of a versatile drywall specialist's toll kit.




Although the foregoing disclosure sets forth the construction of a preferred embodiment of the wipe-down knife of the invention, several alternative versions thereof are contemplated. For example,

FIG. 10

shows a second embodiment


102


of the invention having a bent, offset, blade-mounting plate


104


. Bent plate


104


is very similar to the earlier-disclosed blade-mounting plate


16


, except that it is creased along a line transverse to the longitudinal axis of wipe-down knife


102


, just below bent plate


104


's row of fastening apertures


92


. The extent of the offset in bent plate


104


is a matter of choice, but it has been found that a 33-degree bend provides a comfortable average angle for the user. This angle makes it easier for the user to stand back, away from the wall being worked while wiping it down. This embodiment is also more comfortable to use as a spray shield, to cover an object such as a door or window frame next to a wall being sprayed with paint or plaster.




Yet a third embodiment


106


of the invention is shown in

FIGS. 11

,


12


and


13


. Therein, an alternative, flexible blade-mounting plate


108


is shown to have a butt-type hinge


110


incorporated therein. Flexible plate


108


is comprised of two separate subcomponents: head-engaging portion


112


; and, blade assembly-engaging portion


114


. These roughly correspond to the lower and upper portions, respectively, of plate


16


shown in FIG.


6


A. Hinge


110


connects plate portions


112


and


114


.




Hinge


110


further includes a mechanism which permits the user to set plate portions


112


and


114


securely at any desired angle with respect to one another. For example, for wiping-down ceilings and walls, it is most convenient if plate portions


112


and


114


are set at a 33-degree angle. However, for skip troweling a wall, the user needs to be closer to the wall surface, so an 11-degree angle between plate portions


112


and


114


is best for that purpose.




The mechanism that permits portions


112


and


114


at any desired angle is frictional brake


116


. As shown in

FIG. 12

, frictional brake


116


includes a generally rectilinear housing


118


affixed rigidly to head-engaging portion


112


and covering a portion of hinge


110


. As is well-known in the art of such hinges, a resilient block


120


resides within housing


118


and impinges upon the knuckle of the opposing hinge portion, i.e. upon knuckle


122


of blade assembly-engaging portion


114


. Resilient block


120


should exert sufficient frictional force against the surface of knuckle


122


to permit a user to set a desired angle between plate portions


112


and


114


, and to permit that angle to stay fixed during third embodiment


106


's intended use. It is contemplated that the frictional force needed to keep plate portions


112


and


114


in place may be different for different purposes. For example, if third embodiment


106


is simply used as a paint shield, a great amount of frictional force is not needed to keep hinge


110


in place. However, for troweling and wiping-down wet plaster and other finishing compounds, greater resistance against displacement of plate portions


112


and


114


will be necessary. Thus, frictional brake may be constructed accordingly.




Further, other known mechanisms may be used to improve the action of the hinged blade-mounting plate of third embodiment


106


. For example, plate portions


112


and


114


in third embodiment


106


may be hingedly fastened together with any of a known variety of ratcheting hinges having multiple secure set points throughout a given arc. Hinges of the type having a pair of opposed finger-and-thumb tabs able to be squeezed toward one another against spring pressure to release plates


112


and


114


and let them swivel freely are contemplated. This type of hinge would re-set the angle of plates


112


and


114


securely, once the finger-and-thumb tabs were released.




In use, all embodiments of the inventive wipe-down knife operate similarly in the respect that their blades


20


are able to swivel side-to-side, as shown in FIG.


2


. Although

FIG. 2

only illustrates the range of blade


20


's motion to one side, the construction disclosed herein makes blade


20


able to travel between two fully-opposed positive-stop positions on opposite sides of handle shaft


12


.




The foregoing detailed disclosure of the inventive wipe-down knife in its various embodiments is considered as only illustrative of the preferred embodiment of, and not a limitation upon the scope of, the invention. Neither is its identification as a “wipe-down knife” herein intended to limit the scope of the claims or the invention. Those skilled in the art will envision many other possible variations of the structure disclosed herein that nevertheless fall within the scope of the following claims. For example, different materials may be used in construction of the invention, and all of its elements may be fashioned in different sizes to suit certain purposes.




And, alternative uses for this inventive apparatus may later be realized. For example, in arts or crafts where a spray shield of any type is necessary, the apparatus herein may be used beneficially. And, it would also be a helpful tool in any practice or profession which requires pastey or plastic substances to be spread over a surface or smoothed-out. Yet further, head


14


may be useful for a wider range of purposes than disclosed herein. Indeed, in any case where a planar member must be supported on the end of a handle shaft, use of head


14


may yield superior results. Accordingly, the scope of the invention should be determined with reference to the appended claims, and not by the examples which have herein been given.



Claims
  • 1. A blade base-grasping bracket for a wipe-down knife, comprising:a. a first planar panel projecting in a first plane perpendicular to a longitudinal axis of said bracket; and, b. a second planar panel, integral with said first panel at an apex, projecting in a second plane perpendicular to said bracket's longitudinal axis, said second plane also being generally perpendicular to said first plane, whereby said bracket has a generally L-shaped cross section, wherein said second panel of said bracket projects farther from said apex than said first panel and is folded back toward an interior angle of said apex, such that said folded-back portion of said farther-projecting second panel is parallel to, but spaced apart from, a portion of said second panel which is closer to said apex, thus defining a slot-shaped space therebetween, and wherein a terminal end edge of said folded-back portion of said second panel falls short of abutting said first panel.
  • 2. A blade assembly for a wipe-down knife, comprising:a. an elongate blade base-grasping bracket having a generally L-shaped cross-section comprised of first and second planar panels projecting from an apex, wherein said second panel of said bracket projects farther from said apex than said first panel and is folded back toward an interior angle of said apex, such that said folded-back portion of said farther-projecting second panel is parallel to, but spaced apart from, a portion of said second panel which is closer to said apex, thus defining a slot-shaped space therebetween, and wherein a terminal end edge of said folded-back portion of said second panel falls short of abutting said first panel; and, b. a blade comprising: i. an anchor tab at a base of said blade, said tab being adapted to be received securely within said slot-shaped space bound by opposed inner surfaces of said folded-back second panel of said blade base-grasping bracket; ii. a right-angled nesting portion, integral with and directly adjacent to said anchor tab, adapted to seat nestingly against said interior angle of said apex of said blade base-grasping bracket; iii. a curved hinge portion integral with and directly adjacent to said right-angled nesting portion; and, iv. a working edge portion integral with and directly adjacent to said curved hinge portion.
  • 3. The blade assembly of claim 2, wherein said blade base-grasping bracket and all portions of said blade have substantially the same width.
  • 4. The blade assembly of claim 2, wherein said blade has a substantially uniform thickness throughout.
  • 5. The blade assembly of claim 2, wherein said blade has a plurality of elongate thickened portions parallel to said working edge.
  • 6. The blade assembly of claim 2, wherein said working edge portion of said blade has a working face and a non-working face, and wherein said non-working face includes a plurality of ribs parallel to said working edge.
  • 7. The blade assembly of claim 2, wherein all surfaces of said blade have an axis which is substantially parallel to the length of said blade base-grasping bracket.
  • 8. A wipe-down knife, comprising:a. a handle having a longitudinal axis, a proximal end and a distal end; b. a blade comprising a first planar portion and a second planar portion, said second planar portion being disposed to said first planar portion such that said blade has an L-shaped cross-section; c. means for mounting said blade to said handle's distal end such that said first planar portion of said blade is moveable between being disposed transverse to said handle's longitudinal axis and being disposed substantially parallel to said handle's longitudinal axis, and wherein said second planar portion is disposed such that, as said blade is moved, said second planar portion remains parallel to said handle's longitudinal axis.
  • 9. A wipe-down knife, comprising:a. a handle having a proximal end and a distal end; b. a head at said distal end of said handle, said head having a longitudinal axis, said head also having a slot therein which is open at a distal end of said head and disposed in a plane parallel to said head's longitudinal axis; c. a blade mounting plate disposed swivelingly in said slot in said head; d. a blade mounted upon said blade mounting plate, said blade having a first planar portion which is affixed to said blade mounting plate and which, as said blade mounting plate is swiveled in said slot, is moveable between being disposed transverse to said head's longitudinal axis and being disposed parallel to said head's longitudinal axis, said blade also having a second planar portion which is disposed distally and which, as said blade mounting plate is swiveled in said slot, remains parallel to said head's longitudinal axis.
  • 10. The wipe-down knife of claim 9, wherein said blade mounting plate is T-shaped.
  • 11. The wipe-down knife of claim 9, wherein said blade is mounted upon said blade mounting plate with a blade base-grasping bracket.
  • 12. The wipe-down knife of claim 11, wherein said blade base-grasping bracket comprises:a. a first planar panel projecting in a first plane perpendicular to a longitudinal axis of said bracket; and, b. a second planar panel, integral with said first panel at an apex, projecting in a second plane perpendicular to said bracket's longitudinal axis, said second plane also being generally perpendicular to said first plane, whereby said bracket has a generally L-shaped cross section, wherein said second panel of said bracket projects farther from said apex than said first panel and is folded back toward an interior angle of said apex, such that said folded-back portion of said farther-projecting second panel is parallel to, but spaced apart from, a portion of said second panel which is closer to said apex, thus defining a slot-shaped space therebetween, and wherein a terminal end edge of said folded-back portion of said second panel falls short of abutting said first panel.
  • 13. A head for a wipe-down knife, comprising:a. means for engaging a support for a wipe-down knife blade; and, b. means for mounting said head securely in an open end of a tubular handle, wherein said tubular handle-engaging means includes means for engaging an end edge of a tubular handle, and further includes means adapted to seat deep within said tubular handle and to brace against an inner surface of said tubular handle in response to radially-directed force against said means for engaging a support for a wipe-down knife.
  • 14. The head of claim 13, wherein said means for engaging an end edge of a tubular handle comprises a slightly tapered portion of said head, shaped and dimensioned for secure frictional engagement with a portion of an inner surface of said tubular handle immediately adjacent to said end edge of said tubular handle when said head is driven axially toward said handle, said means for engaging an end edge of a tubular handle further comprising a step adapted to abut said end edge of said tubular handle when said head is driven axially toward said handle.
  • 15. The head of claim 13, wherein said means adapted to seat deep within said tubular handle comprises an elongate lever arm including a plurality of radially-projecting shoes at said lever arm's end, each shoe being adapted to brace against a different portion of said inner surface of said tubular handle in response to differently-directed radial force against said means for engaging a support for a wipe-down knife.
  • 16. The head of claim 15, wherein said lever arm is cruciform in cross-section, being comprised of four elongate, generally rectangular components, each rectangular component projecting radially at a right angle to its two most closely adjacent components, and each bearing one of said radially-projecting shoes on an outermost, endmost edge.
  • 17. A head for a wipe-down knife, comprising:a. means for engaging a support for a wipe-down knife blade, wherein said blade support-engaging means includes means for permitting a support for a wipe-down knife blade to rotate through a planar arc; and, b. means for mounting said head securely in an open end of a tubular handle.
  • 18. A head for a wipe-down knife, comprising:a. means for engaging a support for a wipe-down knife blade, wherein said blade support-engaging means comprises a yoke having a pair of parallel pads and a transverse pivot pin through said pads; and, b. means for mounting said head securely in an open end of a tubular handle.
  • 19. The head of claim 18, further including selectively adjustable means for drawing said yoke's pads closer to one another, whereby said pads may be caused to impinge upon a blade support disposed therebetween.
  • 20. The head of claim 19, wherein said selectively adjustable means for drawing said yoke's pads closer to one another comprises a pivot pin including a threaded portion projecting past an outer surface of a pad of said yoke; a tension-retaining washer engaged with said pin's threaded portion; and, a threaded nut adapted for engagement with said pivot pin.
  • 21. A head for a wipe-down knife, comprising:a. means for engaging a support for a wipe-down knife blade, wherein said support-engaging means comprises a planar slot in a distal end portion of said head, and further, wherein said slot defines and separates a pair of projections projecting from said head, said support engaging means further comprising aligned, fastener-receiving apertures transverse to said slot and through said projections; and, b. means for mounting said head securely in an open end of a tubular handle.
  • 22. The head of claim 21, wherein each said projection is generally planar and includes a widened portion at its distal end.
US Referenced Citations (11)
Number Name Date Kind
1057947 Dietz Apr 1913
2804637 Antozak Sep 1957
3069713 Obraske Dec 1962
3766591 Soito Oct 1973
3803662 Glejf Apr 1974
4520527 Maggio et al. Jun 1985
5261144 Mitchell et al. Nov 1993
5347676 Saitoh Sep 1994
5528793 Schbot Jun 1996
5580608 Capoccia Dec 1996
5930863 Samuelsson Aug 1999
Foreign Referenced Citations (1)
Number Date Country
4447503 Nov 1995 DE