Various tools have been known in the past for working with cements, concretes, mastics and/or muds to, for example, prepare, apply and finish a desired shape or smooth surface for various building surfaces. For example, some tools used for preparing the surface of, for example, concrete, include trowels. Another example are various tools used to prepare and finish, for example, mastics and mud for drywall, including corner finishing boxes, joint boxes, and automatic taper machines. Some examples of various previously known applicators and/or finisher tools may be found in U.S. Pat. Nos. 5,882,691; 6,581,895; and 7,114,869, among others. In any case, these types of tools and corner applicator boxes are typically hand tools that are used to apply and/or smooth various building surfaces such as floors and walls and result in skilled craftsman working on a number of surfaces for long periods of time during the work day. These types of tools are also exposed to bumps and mechanical stresses as well as corrosive substances in their use. Further, various tools may be susceptible to excessive wear due to their design and hard and extensive use in the field. Therefore, it is advantageous to build such tools to be cost effective, light in weight and durable against extensive use. It is also a primary advantage for these tools to apply a quality surface coating which requires a minimum of subsequent process to yield a finished surface. These characteristics are especially advantageous for tools used to finishing various corner regions, for example, inside corner applicator boxes and finishing tools used in drywall construction.
One particular example of corner applicator box 100 is illustrated in FIGS. 1-3 and is typically made in the form of a container or housing that has a plurality of side walls, e.g., side wall 105, a front wall 110, and a bottom wall 115. The top of the container or housing is typically provided by a movable pressure plate 120 which is used to drive out mud (enclosed in the container or housing) through an output port 125 (usually in a bottom wall 115 opposite the pressure plate) when force is applied to the movable pressure plate 120 by the user. A handle attachment bracket 130 is attached to the pressure plate 120 and includes a hole 135 for receiving one end of a handle (not shown). The handle may be used to lift the corner applicator box 100 and push the pressure plate 120 so as to apply mastic or mud to, for example, a drywall surface. A cone piece 140 may be attached to the corner applicator 100 housing. The cone may have a slightly offset center and be similar to, but not exactly, a conical shape so that a nipple 145 of the cone piece 140 is positioned slightly off from the center of the cone and forward toward the front wall 110 and the front of the applicator box 100. It is noteworthy that the angle of both the front wall 140A and the back wall 140B of the cone 140 between a flange end and the nipple 145 are comprised of a single straight continuous line and angle, although each of the front wall 140A and back wall 140B has a different angular pitch. The cone piece 140 has an output port 150 also, comprised of a hole in the nipple 145. Although not shown, the nipple 145 will be pivotably coupled to a corner finishing tool (not shown) having an angle that is in the shape of a triangle so as to fit into the inside 90 degree corner of, for example, a wall or ceiling joint where two walls or the wall and a ceiling of a room come together. The entire cone piece 140 is produced as a single piece made of a single material, e.g., cast from either zinc, aluminum, or stainless Steel. The cast zinc and aluminum versions require a coating to protect the part from the corrosive environment experience with working materials such as mastic or mud, as well as to protect from excessive wear in the connecting ball area 145, which can be exacerbated by the working materials. When the pressure plate 120 is moved toward the bottom wall 115 (pivoting around pivot point 155), mastic or mud placed in the housing will be forced out through output port 125 of the housing, through the cone 140, out the output port or hole 150 of the cone 140, and distributed in a corner joint area of a wall via the finishing tool (not shown). The corner applicator box 100 is typically used for finishing corners of drywall construction for building walls of rooms inside a building (e.g., office or house).
Referring to FIG. 3, the cone 140 construction and means for connecting the cone 140 to the housing are better illustrated. As can be seen from FIG. 3, the widest portion of the cone 140 includes flange 310 with three sides walls 314, 315, and 316. The front side wall 315 of the flange 310 includes two attachment holes through which two bolts or screws are place through this cone 140 front wall 315, and the housing front wall 110, and nuts 325 (or screws) are attached to hold the screws or bolts (or nuts), housing and cone together. As such, either the head of a bolt or screw (or nut) will be extending or protruding from the inner surface of the housing front wall 110 into the interior of the housing. An inner surface 318 of the flange 310 is mounted to the outer surface of the housings bottom surface 115 using three screws 320A, 320B, and 320C. The inner surface 318 of the flange 310 is made so as to be generally flat and smooth. To ensure a leak proof fit between the cone 140 flange 310 and the housing bottom wall 115 and front wall 110, a liquid sealant or glue, for example silicone, is applied to the flange 310 and/or housing wall 115 (and possibly front wall 110) where they interface. Traditionally this joint is sealed using a hand applied sealant which spreads out across the surfaces between the parts at assembly creating the needed seal. This method although functional results in the parts being ‘adhered’ together due to the properties of the sealants used for this task. This bonded joint reduces the efficiency of production and maintaining these tools due to the time involved to place the sealant, remove the excess, and remove it during maintenance should the cone need to be removed for replacement or cleaning.