Apparatus for finishing drywall without sanding

10589311 ยท 2020-03-17

    Inventors

    Cpc classification

    International classification

    Abstract

    A drywall finishing apparatus includes a water reservoir connected to a water distribution element. The water distribution element applies water to a finishing pad. The finishing pad is designed to allow water to flow through and reconstitute already applied drywall mud. The reconstituted drywall mud can then be smoothed out with the finishing pad. The finishing pad creates a hydroplaning effect to glide over the drywall mud.

    Claims

    1. A drywall finishing apparatus, comprising: a water distribution assembly, comprising: a manifold with a plurality of baffles and one or more distribution channels, wherein the plurality of baffles includes one or more curved baffles, wherein the one or more distribution channels include one or more curved distribution channels aligned with the one or more curved baffles; a distribution plate couplable to the manifold, wherein the distribution plate includes a plurality of openings aligned with the one or more distribution channels; and a finishing pad couplable to the distribution plate, wherein the plurality of openings in the distribution plate are configured to distribute water through the finishing pad; and a water reservoir comprising one or more pumps, wherein the water distribution assembly is couplable to the water reservoir.

    2. The apparatus of claim 1, wherein the finishing pad includes a plurality of perforations configured to allow water to pass through from the distribution plate and reconstitute dried drywall mud on a surface.

    3. The apparatus of claim 1, wherein the finishing pad includes a contact surface comprising: at least one of one or more depressions configured to provide a hydroplaning effect to the finishing pad or one or more ridges configured to smooth and redistribute the reconstituted drywall mud without generating drywall dust via sanding.

    4. The apparatus of claim 3, wherein the contact surface is at least 17.5 square inches and not more than 19.5 square inches.

    5. The apparatus of claim 3, wherein the contact surface is at least one of a circular shape, an elliptical shape, a rectangular shape, or a rectangular shape with one or more rounded corners.

    6. The apparatus of claim 1, wherein the manifold is couplable to an extension pole via a swivel mechanism, wherein the extension pole comprises: a check valve, wherein the check valve is configured to prevent water backflow from the manifold; and a switch mechanism coupled to the check valve, wherein the switch mechanism is configured to supply water to the check valve from the water reservoir.

    7. The apparatus of claim 6, wherein the switch mechanism is couplable to the water reservoir via at least one of a quick release element, a water delivery hose, or at least one reservoir valve.

    8. The apparatus of claim 6, wherein the extension pole comprises a water delivery hose, wherein the switch mechanism is configured to supply water to the check valve via the water delivery hose.

    9. The apparatus of claim 1, wherein a pump of the one or more pumps is configured to pressurize water to a flow rate of at least 0.4 pints per minute and not more than 0.75 pints per minute.

    10. The apparatus of claim 1, wherein a pump of the one or more pumps is configured to draw air into the water reservoir.

    11. The apparatus of claim 1, wherein a pump of the one or more pumps is housed within a pump chamber, wherein the pump is configured to remove water from the water reservoir.

    12. The apparatus of claim 11, wherein water at least partially surrounds the pump chamber within the water reservoir, wherein noise generated by the pump housed within the pump chamber is at least partially muffled by the surrounding water.

    13. The apparatus of claim 1, wherein a pump of the one or more pumps is powered by a battery pack.

    14. The apparatus of claim 1, wherein a pump of the one or more pumps is manually-operated.

    15. The apparatus of claim 1, wherein the water reservoir is dimensioned to be wearable on and conform to a back of a user.

    16. The apparatus of claim 15, wherein the water reservoir further comprises at least one of a set of shoulder straps or a belt, wherein the set of shoulder straps and the belt are configured to secure the water reservoir to the back of the user.

    17. The apparatus of claim 1, wherein the water reservoir is dimensioned to hold three gallons.

    18. A drywall finishing apparatus, comprising: a water distribution assembly, comprising: a manifold with a plurality of baffles and one or more distribution channels, wherein the plurality of baffles includes one or more curved baffles, wherein the one or more distribution channels include one or more curved distribution channels aligned with the one or more curved baffles; a distribution plate couplable to the manifold, wherein the distribution plate includes a plurality of openings aligned with the one or more distribution channels; and a finishing pad couplable to the distribution plate, wherein the plurality of openings in the distribution plate are configured to distribute water through the finishing pad; a water reservoir; and a water delivery hose, wherein the water distribution assembly is couplable to the water reservoir via the water delivery hose.

    19. A drywall finishing apparatus, comprising: a water distribution assembly, comprising: a manifold with a plurality of baffles and one or more distribution channels, wherein the plurality of baffles includes one or more curved baffles, wherein the one or more distribution channels include one or more curved distribution channels aligned with the one or more curved baffles; a distribution plate couplable to the manifold, wherein the distribution plate includes a plurality of openings aligned with the one or more distribution channels; and a finishing pad couplable to the distribution plate, wherein the plurality of openings in the distribution plate are configured to distribute water through the finishing pad; a water reservoir comprising one or more pumps, wherein the one or more pumps include at least a pump housed within a pump chamber; and an extension pole coupled to the water distribution assembly via a swivel mechanism, comprising: a check valve, wherein the check valve is coupled to the manifold, wherein the check valve is configured to prevent water backflow from the manifold; and a switch mechanism coupled to the check valve, wherein the switch mechanism is configured to supply water to the check valve from the water reservoir.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    (1) The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which:

    (2) FIG. 1 shows an environmental view of one embodiment of the present invention including a water reservoir connected to an extension pole and finishing head;

    (3) FIG. 2 shows a perspective view of one embodiment of the present invention including an extension pole and finishing head;

    (4) FIG. 3 shows a cross-sectional view of one embodiment of the present invention including an extension pole and valves;

    (5) FIG. 4 shows a perspective view of a water reservoir useful in embodiments of the present invention;

    (6) FIG. 5 shows a view of a water distribution manifold, useful in embodiments of the present invention;

    (7) FIG. 6 shows a close-up, cross-sectional view of a finishing head with a water distribution manifold and finishing pad;

    (8) FIG. 7A shows an alternative shape of a water distribution element;

    (9) FIG. 7B shows an alternative shape of a water distribution element;

    (10) FIG. 7C shows an alternative shape of a water distribution element;

    (11) FIG. 7D shows an alternative shape of a water distribution element;

    (12) FIG. 7E shows an alternative shape of a water distribution element;

    (13) FIG. 8 shows an exploded, perspective view of one embodiment of a drywall finishing apparatus according embodiments of the present invention;

    (14) FIG. 9 shows a cross-sectional view of one embodiment of the present invention;

    (15) FIG. 10 shows a perspective view of a hand-held embodiment of the present invention such as described in FIG. 8 and FIG. 9; and

    (16) FIG. 11 shows a perspective, close-up view of a finishing head of another embodiment of the present invention including an extension pole.

    DETAILED DESCRIPTION OF THE INVENTION

    (17) Reference will now be made in detail to the subject matter disclosed, which is illustrated in the accompanying drawings. The scope of the invention is limited only by the claims; numerous alternatives, modifications and equivalents are encompassed. For the purpose of clarity, technical material that is known in the technical fields related to the embodiments has not been described in detail to avoid unnecessarily obscuring the description.

    (18) Referring to FIG. 1, an environmental view of one embodiment of the present invention including a water reservoir connected to an extension pole and finishing head is shown. In at least one embodiment, a drywall finishing apparatus includes a finishing head 100 to distribute a quantity of water onto applied drywall mud. The quantity of water is sufficient to reconstitute a layer of the drywall mud without compromising the mechanical function of the mud. The finishing head 100 may include a finishing pad to apply the quantity of water and to provide a contact surface to smooth and redistribute the reconstituted mud. In at least one embodiment of the present invention, a contact surface of not more than 19.5 square inches is desirable.

    (19) The finishing head 100 may be connected to a water reservoir 102 through a water delivery hose 106. The water delivery hose 106 may be largely contained within the extension pole 104, or may connect to other water control components contained within the extension pole 104.

    (20) Referring to FIG. 2, a perspective view of one embodiment of the present invention including an extension pole and finishing head is shown. In at least one embodiment, a drywall finishing apparatus includes a finishing head 200 to distribute a quantity of water onto applied drywall mud. The quantity of water is sufficient to reconstitute a layer of the drywall mud without compromising the mechanical function of the mud.

    (21) The finishing head 200 may include a water distribution element 204 and a finishing pad 202 connected to the water distribution element 204. The water distribution element 204 moistens the finishing pad 202 sufficiently to reconstitute drywall mud when the finishing pad 202 is placed in contact with drywall mud during drywall finishing. The finishing pad 202 applies water to the drywall mud, reconstituting the drywall mud sufficiently to allow the finishing pad 202 to smooth the surface of the mud. Because the water is flowing through the finishing pad 202, there is no need for rinsing.

    (22) In at least one embodiment of the present invention, the finishing head 200 is adapted to remove residual mud from bullnose (or round) corners, metal corners, and chamfered corners. The finishing head 200 may be shaped to accommodate such corners and reconstitute excess mud applied to such corners. Excess mud is then smoothed out or removed. Alternatively, a flat finishing head 200 may be manipulated around a corner to reconstitute and smooth a layer of drywall mud. At least one embodiment of the present invention may include a sprayer connected to a water reservoir. The sprayer may be used to directly wet portions of drywall mud at a corner. A drywall finisher may then use a finishing head according to the present invention to smooth such reconstituted mud.

    (23) The finishing head 200 may be connected to an extension pole 206 through a joint 210 such as a universal joint. The joint 210 allows the water distribution element 204 to pivot so that the finishing pad 202 may remain in contact with drywall during finishing. The extension pole 206 may be extendable, with two or more coaxial sections that may be telescopically extended and locked into position. The extension pole 206 allows a drywall finisher to finish sections of drywall mud that may otherwise require stilts or scaffolding. Alternatively, the extension pole 206 may be used in conjunction with stilts and scaffolding to reach applied drywall mud that is otherwise unreachable.

    (24) The drywall finishing apparatus may also include a switching mechanism 208 to control the flow of water to the finishing head 200. The switching mechanism 208 may be embedded in the extension pole 206 at a location easily accessible to a drywall finisher during use.

    (25) Referring to FIG. 3, a cross-sectional view of one embodiment of the present invention including an extension pole and valves is shown. In at least one embodiment of the present invention, a drywall finishing apparatus includes a finishing head 320. The finishing head 320 may include a water distribution element 322. The water distribution element 322 may receive water from a water reservoir and distribute the water substantially uniformly over a finishing pad 324. The finishing pad 324 may include perforations to allow a desirable water flow rate onto already applied drywall mud. The water distribution element 322 may include a manifold to distribute water and a distribution plate to substantially uniformly support a finishing pad 324 while supplying water to the finishing pad 324 through water distribution openings.

    (26) The finishing head 320 may be connected to a swiveling mechanism 318 such as a universal joint to allow the finishing head 320 to rotate or pivot or both. The finishing head 320 and corresponding finishing pad 324 should maintain even contact with the drywall surface during drywall finishing. Unintentional interruption of contact between the finishing pad 324 and the drywall surface may adversely affect the drywall finish, although a person skilled in the art may appreciate that a drywall finishing apparatus according to the present invention may be used to correct irregularities caused by loss of contact.

    (27) The swiveling mechanism 318 connects the finishing head 320 to an extension pole 312 and handle 300. The extension pole 312 may include two or more telescopically extendable sections. The extension pole 312 may also contain water control components to deliver water to the water distribution element 322.

    (28) Water control components may include a check valve 316. The check valve 316 prevents any back-flow of water when the water is not pressurized. Where the extension pole 312 is telescopically extendable, the check valve maybe connected to a coiling hose 314. The coiling hose 314 maintains fluid connectivity when the extension pole 312 is telescopically extended, and also allows the extension pole 312 to be retracted. The coiling hose 314 connects the check valve 316 to a switch mechanism 302. The switch mechanism 302 may include a valve to allow water to flow from a water reservoir to the finishing head 320. Such valve may include a ball valve, needle valve or other suitable flow control mechanism. Furthermore, the valve may be calibrated to allow a desirable flow rate. The switch mechanism 302 may also activate a pumping mechanism to pressurize the water reservoir, such as an air pump. Alternatively the switch mechanism 302 may activate a water pump such as a piston pump to deliver water to the finishing head 320. The switch mechanism 302 may be adjustable such that a drywall finisher may adjust the flow rate of water within a desirable range. The switch mechanism 302 may include a quick release connection point to engage a quick release 304 on a water delivery hose 306. The water delivery hose 306 may further include a quick release (not shown) to connect the water delivery hose 306 to a corresponding quick release connection point on a water reservoir. Quick release 304 elements connecting the water delivery hose 306 to the switching mechanism 302 and a water reservoir allow for greater versatility. For example, a drywall finisher operating on stilts may disconnect the water delivery hose 306 from the switching mechanism 302 to more easily manipulate a water reservoir onto the drywall finisher's back, and then reconnect the water delivery hose 306 to the switching mechanism 302. Alternatively, the water delivery hose 306 may be disconnected from a water reservoir so that the water reservoir may be more easily refilled.

    (29) Referring to FIG. 4, a perspective view of a water reservoir useful in embodiments of the present invention is shown. In at least one embodiment of the present invention, a drywall finishing apparatus includes a water reservoir. The water reservoir delivers water to a finishing head designed to reconstitute a layer of drywall mud so that the mud can be smoothed without sanding. The water reservoir may include a handle 400 for easy transport and a filler cap 402 to access the water reservoir and add water.

    (30) The water reservoir may be wearable. For example, the water reservoir may include shoulder straps 412 and a belt 414 to secure the water reservoir to a drywall finisher's back. In such case, the water reservoir should contain a quantity of water that is safe to transport on the drywall finishers back. In at least one embodiment, the water reservoir may have a capacity of approximately three gallons. A wearable water reservoir should be small enough to allow the drywall finisher access to enclosed spaces such as closets, and should be sufficiently water tight to prevent leakage when the drywall finisher bends over.

    (31) In at least one embodiment, a pump chamber 404 houses a pump 406 and battery pack 408. The pump chamber 404 may be partially surrounded by water in the water reservoir to muffle any noise from the pump 406. The battery pack 408 powers the pump 406 to deliver water, under pressure, through internal plumbing 410 to at least one reservoir valve 416.

    (32) The pump 406 may deliver water at a rate of between 0.4 and 0.75 pints per minute. In testing, a professional drywall finisher was able to finish 57.6 linear feet of mudded seams, and used approximately one pint of water to finish 144 linear feet of mudded seams resulting in a water usage of approximately 0.4 pints per minute. Water delivery of less than 0.4 pints per minute may be insufficient to adequately reconstitute drywall mud. Conversely, water delivery of more than 0.75 pints per minute may saturate a finishing pad to such an extent that the finishing pad reconstitutes more than the desired layer of drywall mud, or water sloshes out of a finishing head uncontrollably.

    (33) Alternatively, a water reservoir may be pressurized by pumping air into the water reservoir through a hand pump 418. In any case, additional water control components may be necessary to restrict the flow of water to a desirable rate.

    (34) Water may be delivered to a finishing head at pressure by other means. For example, an electrically powered piston pump may pump water to the finishing head. Such embodiment may require additional electrical control components such as power and flow control. Such additional electrical control components may be housed in an extension pole.

    (35) Referring to FIG. 5, a view of a water distribution manifold, useful in embodiments of the present invention is shown. In at least one embodiment of the present invention, a drywall finishing apparatus includes a water distribution element with a distribution manifold to deliver water to a finishing pad. The manifold may include baffles 500 defining one or more water distribution channels 502. Baffles 500 prevent water from pooling at one edge of the water distribution manifold due to gravity. Water may be distributed from the water distribution channels 502 through a water distribution plate 504. The water distribution plate 504 may include one or more water distribution openings 506 to evenly distribute water to a finishing pad and to further control the flow rate of water. A finishing pad may be placed over the water distribution plate 504; as water fills the water distribution channels 502 and flows through the water distribution openings 506, the finishing pad may allow water to pass through onto a portion of applied drywall mud. The water reconstitutes a layer of the drywall mud, allowing the reconstituted layer to be smoothed and redistributed.

    (36) Referring to FIG. 6, a close-up, cross-sectional view of a finishing head with a water distribution manifold and finishing pad is shown. A water distribution manifold useful in embodiments of the present invention includes a manifold 600 to receive water from a water reservoir at a desired flow rate. Water may be contained in the manifold 600 by a water distribution plate 602 having one or more water distribution openings 604. The water distribution openings 604 allow water to flow, at the desired flow rate, to a finishing pad 606 attached to the water distribution plate 504.

    (37) Referring to FIGS. 7A-7E, alternative shapes of water distribution elements are shown. While some of the foregoing figures illustrate rectangular water distribution elements and finishing pads, round or elliptical water distribution elements and finishing pads are also contemplated. Round elements may prevent unintentional flipping and gouging during use. For example, FIG. 7A shows a rectangular water distribution element with rounded corners; FIG. 7B shows a rectangular water distribution element; FIG. 7C shows a square water distribution element; FIG. 7D shows a round water distribution element; and FIG. 7E shows an elliptical water distribution element.

    (38) Embodiments of the present invention obviate the need for respiratory masks and protective eyewear by replacing the process of sanding with a dust-free finishing methodology. An apparatus according to the present invention can be used comfortably and safely on stilts and on scaffolds.

    (39) Vacuum systems currently available claim eighty percent to ninety-five percent reduction in dust. Embodiments of the present invention are one hundred percent dust-free because no sanding is required; therefore no dust is ever generated. Also, because no dust is generated, there is no time-consuming and ineffectual clean-up of dust from floors, ledges and sills. In addition, embodiments of the present invention may include a sprayer to directly wet patches of drywall mud that inadvertently dry on floors or sills. The sprayer wets and reconstitutes the patches of drywall mud which may then be wiped off instead of chiseled away. Additionally, during the finishing process, mud is frequently deposited on vinyl window edges. Previously, dried mud would have to be chiseled and pried off of the edge. Utilizing embodiments of the present invention, a sprayer may be used to wet mud deposited on window edges. The deposited mud may then be peeled away easily with a drywall blade or other flat instrument. No chiseling is required, and consequently no dust is generated. Peeling off the deposited mud leaves a clean, smooth drywall edge and provides follow-up painters with a dust free surface to which they may affix masking tape prior to spraying.

    (40) Embodiments of the present invention leave a superior finish as compared to conventional drywall sanding, with none of the scratch marks, roughed paper or residual dust that can mar even the best finished drywall. Furthermore, embodiments of the present invention eliminate the need for back-rolling during painting. Embodiments of the present invention may also allow for improved finishing time. Professional drywall finishers may effectively finish more than fifty-five linear feet of mudded seams per minute.

    (41) Another advantage of embodiments of the present invention over conventional sanding is that the mud does not need to be completely dry before use.

    (42) Referring to FIG. 8, an exploded, perspective view of another embodiment of a drywall finishing apparatus is shown. In at least one embodiment of the present invention, a drywall finishing apparatus includes a water distribution element 800. The water distribution element 800 receives water from a reservoir through a quick release 808 and distributes the water evenly to a finishing pad 802. In at least one embodiment, the finishing pad 802 may include small depressions in the contact surface. Such small depressions contribute to a hydroplaning effect. The finishing pad 802 may also include slightly raised ridges. During drywall finishing, such ridges lay the reconstituted mud flat, filling cracks and gaps. Alternatively, the finishing pad 802 may be substantially smooth or slightly abrasive. A drywall finishing apparatus according to the present invention does not produce any dust because no sanding ever occurs.

    (43) The finishing pad 802 may be removable and replaceable. The finishing pad 802 may include nylon mesh to enhance structural integrity. In at least one embodiment of the present invention, a contact surface of at least 17.5 square inches is desirable.

    (44) The drywall finisher moves the finishing pad 802 along the edges previously requiring sanding, maintaining a steady flow of water through the water distribution element 800. The mud is reconstituted by water flowing onto the surface through the finishing pad 802. Such embodiment may be operable to remove excess mud from outside corners.

    (45) In at least one embodiment of the present invention, the water distribution element 800 and finishing pad 802 may be adapted to remove residual mud from bullnose (or round) corners, metal corners, and chamfered corners. The water distribution element 800 may be shaped to accommodate such corners and reconstitute excess mud applied to such corners. Excess mud is then smoothed out or removed. Alternatively, a flat water distribution element 800 may be manipulated around a corner to reconstitute and smooth a layer of drywall mud. At least one embodiment of the present invention may include a sprayer connected to a water reservoir. The sprayer may be used to directly wet portions of drywall mud at a corner. A drywall finisher may then use a finishing head according to the present invention to smooth such reconstituted mud.

    (46) Because of the lubricating properties of water, the tool effectively is hydroplaning over the surfaces, and does not require the drywall finisher to push up onto the surfaces as he would with a conventional sander. It is therefore much less tiring for the drywall finisher.

    (47) In addition, embodiments of the present invention leave visible wet portions, providing a visible record of where the drywall finisher has been and what still requires his attention. Therefore no areas are inadvertently left unfinished.

    (48) In at least one embodiment of the present invention, the water distribution element is a manifold, though other mechanisms for delivery water from a reservoir to a finishing pad 802 are envisioned. In at least one embodiment, the finishing pad 802 is a sponge.

    (49) In at least one embodiment of the present invention, the finishing pad 802 includes gripping strips 806 to enhance the connection between the finishing pad 802 and the water distribution element 800. Gripping strips 806 may comprise an active fastener such as hook-and-loop fabric, or a passive, friction based element. In at least one embodiment of the present invention, the finishing pad 802 may be secured to the water distribution element 800 with a retention band 804. The retention band 804 may be an elastic band, a strap secured with hook-and-loop fabric, metal fastening band, or any other similar securing mechanism.

    (50) Referring to FIG. 9, a cross-sectional view of one embodiment of the present invention is shown. In at least one embodiment of the present invention, a drywall finishing apparatus includes finishing pad 802 wrapped around a water distribution element 800. The finishing pad 802 and water distribution element 800 remain in contact at least at a portion of the finishing pad 802 corresponding to a contact surface so that the water distribution element 800 may supply water to the finishing pad 802 contact surface.

    (51) The finishing pad 802 may be held in place by a retention band 804. The retention band 804 holds portions of the finishing pad 802 to peripheral surfaces of the water distribution element 800. In at least one embodiment, the finishing pad 802 may include gripping strips 806 interposed between the finishing pad 802 and the peripheral surfaces of the water distribution element 800. The gripping strips 806 may be affixed to the finishing pad 802. Gripping strips 806 may enhance the securing effect of the retention band 804.

    (52) In at least one embodiment of the present invention, the water distribution element 800 may receive water from a reservoir through a quick release 808. The water distribution element 800 may be a manifold with internal spaces defined by baffles 810. The water distribution element 800 may be in contact with a portion of the finishing pad 802 corresponding to the contact surface. Water from the water distribution element 800 may flow through water distribution openings 812 into the finishing pad 802. The water distribution element may receive a substantially continuous flow of water to maintain the moistened state of the contact surface. Such embodiment may include a flow control mechanism on the water distribution element 800 or on a water reservoir connected to the water distribution element 800 through a water delivery hose. The flow control mechanism may include a switch mechanism to control the flow rate of water to the water distribution element 800.

    (53) Referring to FIG. 10, a perspective view of a hand-held embodiment of the present invention such as described in FIG. 8 and FIG. 9 is shown. The embodiment may include a distribution element 800 covered by a finishing pad. The finishing pad may be secured to the distribution element 800 by a retention band 804. A quick release (such as the quick release 808 in FIG. 8 and FIG. 9) may connect to a delivery hose 814. The delivery hose 814 supplies water from a water reservoir.

    (54) Referring to FIG. 11, a perspective, close-up view of a finishing head of another embodiment of the present invention including an extension pole is shown. In at least one embodiment of the present invention, a drywall finishing apparatus includes a finishing pad 1102 with a contact surface for moistening already applied drywall mud. The finishing pad may be secured to a water distribution element with a retention band 1104 securing portions of the finishing pad 1102 to peripheral surfaces of the water distribution element. The water distribution element may be secured to an extension pole 1106 through a universal joint 1110. The extension pole may allow a drywall finisher to reach areas of applied drywall mud that are otherwise inaccessible. The extension pole 1106 may also allow a drywall finisher to finish areas that would otherwise require stilts or scaffolding.

    (55) In at least one embodiment of the present invention, the water distribution element may receive a substantially continuous flow of water through a water delivery hose 1108. The water delivery hose 1108 may connect the water distribution element to a water reservoir. In at least one embodiment, the water distribution element may include a manifold to distribute and continuously supply water to the finishing pad 1102.

    (56) It is believed that the present invention and many of its attendant advantages will be understood by the foregoing description of embodiments of the present invention, and it will be apparent that various changes may be made in the form, construction, and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely an explanatory embodiment thereof, it is the intention of the following claims to encompass and include such changes.