Patent Application
20090255212
This invention relates generally to the application of mastic at corners defined between converging adjacent sheets of drywall, and more particularly to the application of mastic at corners of different angles, including non-right angle corners.
In houses and other buildings, drywall is commonly used as interior wall finishing. Large sheets of drywall are fixed to the wall framing in adjacent positions to cover the framing, cracks or gaps between adjacent drywall sheets being subsequently covered with tape and mastic that is allowed to dry and then sanded to form a smooth joint between the drywall sheets to finish the interior wall covering. A number of tools have been developed for applying a relatively controlled, clean and consistent later of mastic, some designed for application between parallel drywall sheets at flat wall sections, other designed for application along corner edges defined between two converging sheets of drywall.
The latter type of tools includes tools designed for use at frequently found ninety degree corners. Tape and mastic application at a number of corners of varying angles thus has conventionally involved using common ninety degree tools at the more typical or standard ninety degree corners and performing manual application of mastic using a knife or similar tool at other corners. Such manual application relies on skill and experience to form a clean, uniform deposit of mastic along the corner to provide an aesthetically pleasing joint, and typically requires significantly more time than tool-assisted application at standard ninety degree corners.
One proposed solution to reduce the time needed to manually finish non-right angle corners has been to create corner finishing tools for particular non-right angle corners, for each such tool the two faces at which the mastic is applied against the two drywall sheets diverging at a predetermined angle corresponding to the particular non-right angle of the corner in which the tool is to be used. While a person could obtain a number of such non-right angle tools for use at a number of particular corner angles, the person would still need to rely on manual application at other non-standard angled corners and would need to incur the cost of obtaining a plurality set of mastic application tools. Using this approach, switching from one mastic applicator to another is necessary on a jobsite having a number of differently angled corners.
According to a first aspect of the invention there is provided a variable angle mastic applicator comprising:
a first panel;
a second panel pivotally connected to the first panel to allow pivoting of the second panel relative to the first panel along an axis extending along the first panel; and
a delivery passage communicating at opposite ends with opposite sides of the first and second panels to allow delivery of mastic from a source side of the first and second panels to an application side of the first and second panels;
the pivoting of the second panel relative to the first panel about the axis allowing change of an angle at which the first and second panels diverge from one another.
Preferably the second panel is biased to pivot about the axis in a direction reducing the angle at which the first and second panels diverge, measured on the application side of the fist and second panels.
Preferably the second panel is biased by a torsion spring connected between the first and second panels on the source side thereof.
Preferably pivoting of the second panel relative to the first panel is limited to prevent increase of the angle at which the first and second panels diverge to more than 180 degrees, measured on the source side of the first and second panels.
Preferably there is provided a diverter carried on the first and second panels on the application side thereof to guide mastic delivered through the delivery passage laterally outward therefrom in directions transverse to the axis toward an outer edge of each panel distal to the axis.
Preferably the delivery passage extends through only the first of the first and second panels.
Preferably the first and second panels overlap at an inner edge of each panel proximate the axis, the axis being offset from the inner edges of the panels to the source side thereof.
Preferably the first panel overlaps the second panel on the application side of the first and second panels.
Preferably a portion of the first panel overlapping the second panel curves about the axis toward the inner edge of the first panel.
Preferably each panel comprises a retaining lip projecting to the application side of the first and second panels along an end of the panel oriented transverse to the axis.
Preferably each retaining lip has a first leg projecting outward from a base surface on the application side of the panel and a second leg projecting along the base surface at a distance therefrom from an end of the first leg opposite the base surface.
Preferably each panel comprises a rail extending along an outer edge of the panel distal to the axis on a base surface on the application side of the panel.
Preferably each rail projects further from the base surface at one of the rail than at an opposite end of the rail.
Preferably there is provided a stop carried on the first panel on the source side of the first and second panels to limit the pivoting of the second panel in a direction decreasing the angle at which the first and second panels diverge, measured on the source side of the first and second panels.
Preferably there is provided a connection body carried on the first and second panels on the source side thereof and adapted for connection to a mastic delivery device.
Preferably the connection body comprises a socket for receiving a ball end of the mastic delivery device, the delivery passage communicating with the socket on the source side of the first and second panels.
According to a second aspect of the invention there is provided a method of applying mastic to a corner defined between two sheets of drywall, the method comprising the steps of:
(a) providing a variable angle mastic applicator comprising a first panel, a second panel pivotally connected to the first panel to allow pivoting of the second panel relative to the first panel along an axis extending along the first panel and a delivery passage communicating at opposite ends with opposite sides of the first and second panels to allow delivery of mastic from a source side of the first and second panels to an application side of the first and second panels;
(b) pivoting of the second panel relative to the first panel to change an angle at which the first and second panels diverge to generally match a corner angle defined by the sheets of wall drywall; and
(c) delivering mastic through the delivery passage of the applicator with each panel of the applicator having been placed against a respective one of the sheets of drywall adjacent the corner.
Preferably the second panel of the applicator is biased to pivot about the axis in a direction increasing the angle at which the first and second panels diverge, measured on the source side of the first and second panels, and step (b) comprises forcing panels of the applicator against the respective sheets of wall drywall to overcome the biasing of the second panel and force the angle at which the first and second panels diverge to change to generally match the corner angle.
In the accompanying drawings, which illustrate an exemplary embodiment of the present invention:
The figures show a mastic applicator 10 of the type having a generally hemispherical hollow socket cavity 12 therein for receipt of a ball-shaped outlet of a mastic delivery tool (not shown) so that mastic discharged from the delivery tool exits therefrom through an outlet port in the ball into a delivery passage 14 of the applicator communicating with the socket 12. The applicator 10 improves on prior art applicator's of this type in that the faces of the applicator 10 at which the mastic material is applied to a pair of drywall sheets defining a corner at the border defined between the drywall sheets at adjacent edges thereof are defined by two panels 16, 18 that are pivotally interconnected to allow an angle at which the panels diverge from one another to change to facilitate the use of the applicator 10 at corners of different angles.
A connection body 20 includes a solid block 22 having a rectangular vertical planar rear face 24 from which the hemispherical socket 12 projects into the solid block 22 at a position inward from the perimeter of the rectangular face 24. A first vertical side 26 of the block 22 projects perpendicularly from the rectangular rear face 24 to the rear side of the first panel 16, as shown in
Two channel defining projections 30 of the connection body 20 extend along respective opposite sides of the rear face 24 where the sides 26, 28 of the block 22 connect to the rear face 24. Each projection 30 has an L-shaped horizontal cross section, with a first leg 30a projecting perpendicularly from the rear face 24 and a second leg 30b projecting parallel to the rear face 24 inwardly thereover toward the opposite one of the two projections 30. This defines an elongate channel 32 between the rear face 24 and the second leg 30b. The two parallel channels proximate opposite sides of the rear face 24 house two respective legs of a spring clip 34. The legs of the spring clip 34 are bent toward one another to jut slightly inward over the hemispherical socket 12 opening into the block 22 from the rear face 24 thereof at diametrically opposite positions thereabout just inward from the channels 30. The spring clip 34 thus functions in a known manner to retain the ball of a mastic delivery device in the socket 12 after the ball is forced against the spring clip legs to force them apart and slide into the socket 12. The spring legs are biased to move apart, thus holding the clip 34 in place against the first legs 30a of the projections 30 at opposite ends of the channels 30 where the bent shape of each leg curves outward past the closed side of the respective channel 32 defined by the respective first leg 30a.
Above and below the connection body 20, the second panel 18 is pivotally connected to the first panel 16 to facilitate relative pivoting of the two panels about a vertical axis parallel to the two vertically oriented panels 16, 18. The first and second panels 16, 18 feature top and bottom flanges 36, 38 projecting horizontally rearward from the top and bottom ends of the panels so that the two flanges 38 of the second panel 18 are positioned between the two flanges 36 of the first panel 16, the connection body 20 being positioned between the two flanges 38 of the second panel 18. A pivot pin 40 passes through each of the two flange pairings at the top and bottom of the panels 16, 18. That is, one pivot pin passes through the first panel flange and the second panel flange at the generally aligned top ends of the two panels 16, 18 and another pivot pin passes through the first panel flange and the second panel flange at the generally aligned bottom ends of the two panels 16, 18, the two pivot pins being axially aligned with one another and thus defining the pivot axis of the panels. In the illustrated embodiment, each pivot pin 40 is defined by a screw extending through the respective pair of flanges and fixed in place with a nut on the side of the flange pair opposite the screw head.
A torsion spring 42 is mounted atop the top end face 44 of the solid block 22 of the connection body 20 and biases the second panel 18 about the pivot axis into a distal position, best shown in
The solid block 22 of the connection body 20 fixed to the first panel 16 helps limit the pivotal motion of the second panel 18 relative to the first panel 16. The pivoting of the second panel 18 about the pivot axis against the bias of the torsion spring is limited by eventual contact of the rear face 18a of the second panel 18 with the second side 28 of the block 22. Pivoting of the second panel 18 in the opposite direction about the pivot axis is limited by eventual contact of an inner edge 18b of the second panel 18, parallel and nearest to the pivot axis, with the same second side 28 of the block 22 along the edge defined at the meeting of this second side 28 and the front face of the block 22 where the block is fixed to the rear surface 16a of the first panel 16. The block 22 of the connection body 20 thus acts as a stop limiting the pivoting of the second panel 18 relative the first panel 16 in each direction about the pivot axis.
Horizontally along the vertical plane in which it lies, the rear face 24 of the solid block 22 of the connection body 20 is generally centered between the outer edges 16c, 18c of the panels 16, 18 when the second panel 18 is in its biased distal position spaced furthest from the second side 28 of the block 22 and the socket cavity 12 spanning generally fully between the projections 30 at the opposite sides of the rear face 24 is horizontally centered on the rear face 24. The delivery passage 14 extends generally perpendicularly and cylindrically from the first panel 16 through the solid block 22 of the connection body into the generally hemispherical socket cavity 12. The delivery passage 14 extends through an opening in the first panel 16 having the same shape as the cross section of the delivery passage, thus fluidly communicating the socket 12, where mastic is to be delivered by a suitable source such as a plunger-equipped tubular handle with a ball-forming outlet-equipped end, with the opposite side of the panels 16, 18 where the mastic is to applied to drywall during movement of the applicator along a corner defined between adjacent drywall sheets.
The axis of the generally cylindrical delivery passage 14 is not aligned with the axis of the generally hemispherical socket cavity 12, but rather is generally perpendicular to the front face of the connection body's solid block 22 and the first panel 16 fixed flush thereon. As a result, the axis of the delivery passage is oblique to the rear face 24 of the connection body's solid block 22 within a horizontal plane perpendicular thereto, as illustrated by the visibility of delivery passage side wall 14a nearest the second panel 18 in
To prevent the opening of a gap between the panels 16, 18 during relative pivoting therebetween, the panels 16, 18 overlap each other at their inner edges 16b, 18b, the first panel 16 being positioned on a side of the second panel 18 opposite the connection body 20. Over its full height between its pivot flanges 36, the first panel 16 traverses the pivot axis and then curves concentrically about the pivot axis for a relatively small distance approaching the inner edge of the panel 16b. About the pivot axis, the curve radius of this edge portion 50 of the first panel 16 defining the inner edge 16b is slightly greater than the arcuate path followed by the inner edge 18b of the flat second panel 18 during pivoting thereof about the pivot axis. As a result, the inner edge 18b of the flat second panel moves along the curved inner edge portion 50 of the first panel 16 in close proximity thereto or light contact therewith to prevent significant leakage of mastic between the panels from the application side thereof back through to the opposite source side where it was initially delivered to the applicator in the socket 12. The arcuate length of the curved portion 50 of the first panel 16 and the amount of pivoting allowed before the rear surface 18a of the second panel 18 contacts the second side 28 of the connection body's solid block 22 cooperate to prevent movement of the second panels inner edge 18b past general alignment with the parallel vertical inner edge 16b of the first panel about the pivot axis.
As the curved inner edge portion 50 curves rearward from the flat or planar rest of the panel about the pivot axis, it prevents pivoting of the second panel 18 into an aligned parallel position with the flat portion of the first panel. A front face 18d of the second panel comes into contact with the first panel's inner edge 16b at the curved inner edge portion 50 as the inner edge 18b of the second panel comes into contact with the solid block 22 of the connection body 20 at the connection thereof to the rear face 16a of the first panel during movement of the second panel 18 into the biased position where the divergent angle of the flat second panel 18 and the flat portion of the first panel 16 outward from the curved inner edge portion 50 on the same side as the connection body 20 is at its maximum and the rear face 18d of the second panel is accordingly at its angular furthest from the second side 28 of the connection body's solid block 22. The stop defined or carried on the first panel 16 to block pivoting of the second panel 18 past this position is thus defined not only by the connection body's solid block 22, but also by the first panel itself, at the rear or source side of the first panel at or proximate the inner edge 16b, thus at the curved edge portion 50 in the illustrate embodiment. It will be appreciated that other embodiments may make use of only one of these two stop configurations and still act to define one of the two limits of the second panel's pivotal motion range.
At the front faces 16d, 18d of the panels 16, 18, opposite the rear faces 16a, 18a and facing away from the connection body 20, a pair of rails 51 are provided, each extending along a respective one of the outer edges 16c, 18c of the two panels 16, 18 from adjacent the horizontal upper end of the panel to a position spaced upward from the opposite horizontal bottom end of the panel 16. As shown in
At the front face 16d of the plate forming the first panel 16, opposite the rear face 16a and thus facing away from the connection body 20, a diverter 52 is positioned over the opening in the panel 16 at the respective end of the delivery channel 14, as shown in
As shown in
When mastic is delivered through the passage 14, it is diverted laterally outward to both sides along the first panel 16, with the diverter-defined path being more open on the side nearest the second panel 18 so that more mastic will flow in that direction. This arrangement aims to more evenly distribute the mastic over the front panel faces 16d, 18d, as the positioning of a single delivery channel at the first panel 16 only may otherwise tend to cause a build up of mastic on the application side of the first panel 16, with the second panel 18 receiving less mastic. As shown in
Toward the outer edge 16c of the first panel 16, the diverter extends just past the respective side of the delivery passage 14, leaving an uncovered span of the first panel's front surface 16d between the diverter 52 and retaining lips 49 that are provided to block mastic from leaking out over the top edges of the panels after being delivered to the application side thereof during use of the applicator. Each retaining lip 49 extends from adjacent the top pivot flange of the respective panel fully outward to the respective rail 51 and features a first leg 49a projecting perpendicularly from the panel to the same side thereof as the rail 51 at the panel's top edge and a second leg 49b projecting downwardly along the front surface of the panel or the rail 51 from an end of the first leg 49a opposite the panel.
The illustrated embodiment adapter 10 is arranged for use on inside corners, as the angle at which the panels diverge away from one another, measured on the same side of the panels as the connection body 20 where mastic is delivered from a source to the applicator 10, does not increase to above 180 degrees. This angle may minimize to a value of approximately 90 degrees when the second panel 18 is pulled fully out of the biased position into engagement against the second side 28 of the connection body block 22, as conventionally constructed homes and buildings tend to feature inside corners of 90 degrees and larger. In use, the applicator 10 is mounted on the end of a mastic delivery device by cooperation of the applicator's socket 12, the delivery device's ball connector and the spring clip 34 in a known manner so that operation of the delivery device will force mastic from the source enclosure of the device through an outlet in the ball connector thereof for subsequent flow through the delivery passage 14 communicating through to the opposite side of the first panel 16.
By using the delivery device to apply force against the applicator 10 at the ball and socket connection, the two panels 16, 18 are pushed against respective ones of two drywall sheets defining the inside corner to which the mastic is to be applied. Provided that the corner angle, measured on the side of the drywall to which the mastic is to be applied, is less than the corresponding divergent angle of the panels, thus measured on the source side thereof (the same side as the connection body), with the second panel in its biased position, the opposition of the walls to the force applied on the applicator toward the corner pivots the second panel 18 out of the biased position toward the second side 28 of the solid body 22 of the connection block 20 until the panels 16, 18 have taken on a position relative to one another in which their divergent angle on the source side of the panels matches the corner angle. Maintaining a force on the applicator sufficient to maintain this orientation between the panels, mastic is delivered through the delivery passage 14 into the space between the front faces 16a, 18a of the panels and the drywall sheets and bound at the sides (outer edges of the panels) and top of the applicator by the rails 51 and retaining lips 49. Still maintaining the force to overcome the torsion spring bias and keep the panels 16, 18 and rails 51 held against the drywall, the applicator is slid up along the corner, applying a layer of mastic to each sheet of drywall along the bottom of the respective applicator panel below the rails 51.
It will be appreciated that as an alternative to biasing the panels into relative positions at which their divergent angle on the application side is at a minimum, it may be possible to provide other embodiments in which the panels instead are lockable into any one of a number of preselected relative angular positions, for example by using locking pins passable through an aperture in each the first panel's pivot flanges 36 that aligns with a respective one of a plurality of apertures arcuately spaced about the pivot axis in the second panel's respective pivot flange 38 in each of a plurality of angular positions of the second panel relative to the first. However, the use of spring biasing in the illustrated embodiment to cooperate with user applied force on the applicator allows adjustment of the applicator to any angle within the second panel's range of movement, rather than to a limited finite number of angular positions, thus providing the best fit for any corner in which the applicator is to be used, rather than the best available approximation selectable by the user.
From the forgoing description, it should be appreciated that the terms vertical and horizontal are used with reference to the illustrated orientation of the applicator in the figures, in which the generally flat panels are oriented vertically, but that in use of the applicator on corners defined between adjacent vertical walls the panels will be positioned in nearly vertical upright orientations, but not completely vertical due to the slope of the front surfaces of the rails 51 that sit flush against and slide along the vertically oriented drywall sheets. It will also be appreciated that the applicator can be used in corners of other orientations, for example between a vertical wall and a non-horizontal sloped ceiling section.
Although the illustrated embodiment is arranged for use on inside corners, it may be possible to produce a similar applicator for use on outside corners. In such an embodiment, rather than a hinged or pivoting pair of panels having a divergent angle between them on a source side of the panels opposite a connection body 20 fixed to one of the panels being adjustable through a range defined between 90 and 180 degrees, this angle could instead be adjustable through a ranged defined between 180 and 270 degrees, a torsion spring again biasing these panels in a closing direction tending to increase this angle to an upper limit of its range and the connection body being shaped to define a stop to prevent movement of the movable panel past a position at which this angle is at a lower limit of its range. This way the angle on the application side of the panels opposite the connection body is adjustable within a range of 90 and 180 degrees to accommodate a corresponding range of outside or exterior corner angles between the panels. In such an arrangement, a hinge may be used to pivotally connect non-overlapping inner edges of the two panels to position the pivot axis adjacent the front faces of the panels, nearer thereto than the pivot axis of the illustrated embodiment which is offset from the panels by the flanges 36, 38. A diverter may still be used to guide mastic flow laterally outward when exiting the delivery passage on the application side of the panel fixed to the connection body, but extending toward the inner edge of this fixed panel only so far as to leave sufficient space between this end portion of the diverter and the front face of the pivoting panel when moved to its angular position about the pivot axis nearest to the front face of the fixed panel to allow mastic to flow out from channel defined between the diverter's central portion and the front face of the pivoting panel. The angles between the panels of this alternate embodiment on the application side not exceeding 180 degrees like in the illustrated embodiment, the end portion of the diverter's central panel should not curve about the pivot axis. The stop defining the lower limit of the second panel's pivotal range, at which the angle between the panels on the application side is at a minimum, may be defined by contact between the flat panels near their inner edges.
Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
