The present invention relates generally to: tools, equipment, and related devices that dispense semi-fluid compounds; procedures for using same; and in particular to an applicator system for finishing drywall and other surfaces.
Drywall installation typically involves joining two or more panels or sheets of gypsum board together to create a larger surface, such as a wall or ceiling. This is accomplished by taping the joints and covering the tape with joint compound (or “mud”). Additional applications of mud can be used depending on the specified level of surface finish. Some drywall finishers prefer to apply the mud by hand using putty knives, but this can be a time-consuming process. To semi-automate the process, tool manufacturers have created “flat boxes” comprising reservoirs attached to handles for guiding along gypsum board or drywall joints. The flat boxes apply joint compound, normally over a strip of joint tape, along joints. The joint compound can be sanded and re-coated as necessary to achieve the specified finish level. There are also corner tools and associated reservoirs that apply mud to corner joints. The user applies pressure via a handle assembly to dispense the mud while pushing or pulling such applicators along the drywall joints.
Previous drywall finishing tools include the Continuous Flow Paste Applicator for Dry Wall shown in U.S. Patent Publication No. 2001/0003563, but the connected hoses required by this applicator can be unwieldy. Other prior art finishing systems include components that must be carried around with handle systems, e.g., as shown in U.S. Pat. No. 6,793,428 for Drywall Joint Compound Applicator Appliance, or continuously dispense compound until a brake is applied, which can lead to the tool dispensing excess compound.
There is needed in the art a handle system that will automatically dispense drywall joint compound, with a flow-driving mechanism that can be engaged without changing the position of the finishing tool relative to the work surface, and that does not tether the user due to the lengths of attached hoses and/or power cords.
Heretofore, there has not been available a surface finishing system with the features and advantages of the present invention.
In practicing an aspect of the present invention, a system is provided for automatically applying a finishing compound to a surface, e.g., joint compound (“mud”), which can be applied over joint tape to form a flush or level drywall joint. Modified or alternative aspects of the invention include lockable gas springs, piston-and-cylinder units and drive augers for dispensing the compound from a handle assembly, which can be held by an operator. Power can be applied via compressed springs extending a plunger or electric motors rotating an auger. Various application-specific finishing tools, such as mud knives for flat surfaces and corner tools (e.g., for wall-ceiling and wall-wall intersections), can be mounted on the handle assembly.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention illustrating various objects and features thereof:
As required, detailed aspects of the present invention are disclosed herein, however, it is to be understood that the disclosed aspects are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art how to variously employ the present invention in virtually any appropriately detailed structure.
Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, up, down, front, back, right and left refer to the invention as orientated in the view being referred to. The words, “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the aspect being described and designated parts thereof. Forwardly and rearwardly are generally in reference to the direction of travel, if appropriate. Said terminology will include the words specifically mentioned, derivatives thereof and words of similar meaning.
Referring to
A handle 14 can extend the distance between a user and the intended application surface 7. Various embodiments of certain features of the invention can also be mounted onto or in the handle 14.
The extendable-retractable handle 14 can include one or more sections 14a, 14b, etc., which can telescope with respect to each other. A pressurized cylinder 30 can be mounted in the handle 14 for dispensing a quantity of material 6, such as drywall finishing compound or “mud.”
A tool assembly 4 includes a release lever 12, which is actuated by squeezing the lever 12 towards the body of the handle 14, thereby retracting a master rod 32 which rotates a first embodiment braking mechanism 38 (in this case, a pinch brake 40) thereby releasing a slave rod 34 which is a piston of the pressurized cylinder 30. The piston 34 is connected to the reservoir plunger 18. With the release lever 12 depressed, gas and/or spring pressure within the cylinder 30 pushes the slave rod 34 outwardly for continuous compound 6 dispensing until the release lever 12 is released or the handle reservoir 16 requires recharging with compound material 6.
Upon releasing the lever 12, a first embodiment brake compression spring 42 (compressed with the retracted master rod 32) expands and extends the master rod 32, rotating the pinch brake 40 of the braking mechanism 38 in the opposite direction, thereby braking the outward motion of the slave rod 34.
Reversing the direction of the slave rod 34 follows a sequence similar to that of the standard use sequence: squeezing the lever 12 retracts the master rod 32, which rotates the braking mechanism 38, thereby releasing the slave rod 34, at which point inward pressure on the opposite end of the piston 34 would re-pressurize the gas and/or spring pressure within the cylinder 30 with the slave rod 34 returned to its initial position, ready for the process to be repeated, and for recharging or reloading the reservoir 16 with drywall compound 6.
A second embodiment or aspect of the invention comprising a system designated 102 with a compound-dispensing tool 104 incorporates the use of a cam 150 in place of a pinch brake 40 and is shown in
Similar to the operation of the previous embodiment, upon releasing a release lever 112, a second embodiment brake compression spring 152 squeezed by a retracted master rod 132 is allowed to expand, thereby extending the master rod 132, rotating the cam 150 of a braking mechanism 148 (in this case, a cam brake) in the opposite direction, thereby braking the outward motion of the slave rod 134.
The handle 114 can include one or more sections 114a, 114b, etc. and can be connected to a source of the compound 6 for reloading or recharging a reservoir 116 as the material 6 is applied and used. A reservoir plunger 118 can be mounted to the end of the slave rod 134 to ease dispensing. Alternative arrangements for locking and releasing the piston rod 134 of a piston 134 and cylinder 130 unit are provided. These can include, without limitation, rotatable plates, cams, and other braking mechanisms. A non-limiting example of an application for the extendable handle 114 is a drywall finishing tool 104 mounting a drywall compound (mud) distribution box 8, as well as various other taping, sanding, painting, and finishing tools and equipment.
The system 102 can, similarly to the previous embodiment, incorporate a fill access port 122, a ball valve throttle 124, and one or more openable clamp assemblies 120 to simplify use.
A third embodiment or aspect of the invention (
Upon release of the trigger 212, the release pin 264 is no longer depressed and the locking, pressurized gas cylinder 268 locks, thereby braking the outward motion of the plunger 218.
Reversing the direction of the cylinder 268 follows a sequence similar to that of the standard use sequence: squeezing the trigger 212 depresses the release pin 264, thereby unlocking the pressurized cylinder 268, at which point inward (retracting) pressure on the opposite end of the cylinder 268 would re-pressurize the gas pressure within the cylinder 268 and return the cylinder 268 to its initial position relative to the piston rod 266, ready for the process to be repeated.
The system 202 can also include a trigger latch 260.
Alternatively, the dispensing-locking positions of the trigger mechanism 212 can be reversed whereby squeezing the trigger mechanism 212 causes the tool assembly 204 to dispense material. The operation of the latch 260 can likewise be changed as appropriate for particular applications and to accommodate user preferences.
The system 202 can, similarly to the previously-described embodiments, incorporate a fill access port 222, a ball valve throttle 224, and/or one or more openable clamp assemblies 220 to simplify use.
Yet another alternative embodiment or aspect of the invention (
Alternatively, the motor 378 can drive a threaded shaft threadably connected to a plunger 318 for expelling the material 6 contents of the reservoir 316. Upon release of the trigger 312 the motor 378 is no longer powered and ceases to rotate the shaft 382, thereby stopping the discharge flow of material 6.
A variable- or static-speed forward/reverse (reverse optional) switch 380 can be included in the assembled tool 304. The switch 380 can control the speed and rotational direction of the motor 378 and can be housed with the motor 378 within the motor housing 376. The switch 380 can include forward and reverse closed positions for dispensing compound 6 or reloading (recharging) the reservoir 316, or retracting the plunger 318.
Threaded rods, plungers and other operative components can be utilized with a reversible electric motor, such as the drive motor 378. Moreover, compound materials 6 can be loaded into and discharged from hollow portions of handles (e.g., 314) and/or reservoirs (e.g., 316) using suitable augers or shaft-plunger assemblies, which are rotated by the drive motor 378. For example, the threaded shaft 386 could extend through most of the length of the reservoir 316 and threadably mount the plunger 318 thereon for advancing and retracting through the reservoir 316 in a reciprocating range of motion.
Another embodiment of a potential mating connection between the motor 378 and the auger shaft 382 is shown in
The battery 374 can be recharged by removing it from the assembled tool 304 and connecting it to a charger 390 (
The system 302 can, similarly to the previous embodiments, incorporate a fill access port 322, a ball valve throttle 324, and one or more openable clamp assemblies 320 to simplify use.
It is to be understood that while certain embodiments and/or aspects of the invention have been shown and described, the invention is not limited thereto and encompasses various other embodiments and aspects.
This application claims priority in U.S. Provisional Patent Application No. 62/401,579, filed Sep. 29, 2016, which is incorporated herein by reference.
Number | Date | Country | |
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62401579 | Sep 2016 | US |