Mounting systems for under mount sinks

An improved mounting system for clamping sinks, vanity basins, drop-in stove tops and like articles to the underside of a counter or cabinet top incorporating a pair of elongated unitary, rigid mounting rails configured to carry threaded leveling bolts and nuts at adjustably spaced intervals along its length for underengaging and clamping the rim flange at the upper end of the sink or the like to the underside of a countertop. Hanger brackets attachable to the upper margins of countertop supporting cabinet structural frame rails or walls provide vertically adjustable connection with opposite ends of the mounting rails mounted thereon to accommodate sinks, basins or stove tops having rim flanges of varying thickness and dimensions.

FIELD OF THE INVENTION 
This invention is related generally to an improved system for clamping and 
mounting sinks, basins, drop-in stove tops and similar articles to the 
under side of cabinet countertops whereby the sink or basin may be 
adjustably leveled and secured in operating position opposite an overlying 
access opening in the countertop. 
BACKGROUND OF THE INVENTION 
Undermount sinks, basins and the like have heretofore been mounted to the 
underside of cabinet countertops opposite an overlying access opening in 
the countertop by means of a series of spaced, individual adjustment 
brackets and leveling bolts anchored directly to the underside of the 
countertop giving rise to possible damage of the countertop by the 
installer. The brackets are individually located and adjusted to engage 
the underside of the sink's rim flange extending about the open end of the 
sink bowl whereby to force the flange tightly against the bottom side of 
the countertop. This system requires careful and time consuming adjustment 
and alignment of the many individual adjustment brackets and frequently 
requires shims and the like to achieve a level sink position, particularly 
if the cabinet itself or the countertop is not horizontal. 
More recently a variation of the aforenoted individual bracket mounting 
system has been presented employing a pair of lengthwise adjustable, 
two-piece, stamped metal brackets having upturned attachment arms at the 
outer ends of linear bracket sections for securing the same to and between 
spaced sides or frame rails of the cabinet. The two bracket sections are 
bolted together at overlapping end portions thereof and within slotted 
openings to accommodate limited lengthwise adjustment of the assembled 
brackets. Each bracket carries several leveling bolts threaded through 
openings at fixed positions therealong for underengaging and clamping the 
sink flange against the underside of the countertop. While this system 
appears to be an improvement over the individual bracket system noted 
above, in that the leveling bolts thereof are positioned and held by the 
two-piece elongated bracket, the limited fixed spacing and location of the 
leveling bolts frequently fails to accommodate multiple sink sizes and 
provide the necessary flexibility to meet a variety of other installation 
requirements. Additionally, the need to fix the two sections of each 
adjustable bracket together results in a weakened support structure 
especially when the brackets are extended to their full length to meet 
cabinet dimensions. This seriously detracts from the clamping action 
motion of the leveling bolts. While this support system is sufficient to 
support lightweight sinks, it is not satisfactory under the load of 
heavier articles, such as cast iron, ceramic or composite sinks and heavy 
drop-in stove tops. Currently, these heavier articles are usually under 
supported directly on heavy wooden frames built into the cabinet at 
installation of the sink or stove top. 
This invention is directed to overcoming the aforenoted problems and 
deficiencies of prior support assemblies utilized to undermount sinks, 
basins and like items beneath a cabinet top or the like. 
BRIEF SUMMARY OF THE PRESENT INVENTION 
Briefly, the mounting system of this invention comprises a pair of rigid, 
extruded metal rail members having a cross sectional configuration 
designed to slidably accommodate leveling bolts and nuts. Upper walls of 
the rail members are distinguished by plural-spaced slotted openings 
through which the leveling bolts may be extended as selected. A pair of 
mounting brackets cooperate with the opposite ends of each rail to fix the 
rail at selected elevations beneath the cabinet countertop. Each bracket 
has a linear leg adapted to be fastened securely to the interior of a 
cabinet wall or horizontal support rail. A planar arm preferably extends 
across the upper end of the bracket leg to overhang the top of a cabinet 
wall or support rail. A plurality of spaced connector fingers project from 
one side of the bracket leg for insertably or abuttingly engaging and 
interconnecting with the ends of an associated support rail. Various 
dimensional distances between cabinet walls or support rails are 
accommodated by cutting the support rails to length as needed. 
It is an important object of this invention to provide a new and simplified 
support assembly for mounting stainless steel, cast iron, porcelain steel 
sinks and vanity basins, drop-in stove tops, and like articles beneath an 
opening in a countertop without connecting fasteners to the countertop. 
Still another object of this invention is to provide an improved positive 
mounting system for undermounting cast iron, ceramic or composite material 
sinks, basins and like heavy articles to the underside of countertops. 
A further object of this invention is to provide an improved mounting 
system as set out in the preceding object which provides a positive and 
rigid mount capable of readily leveling and clamping undermount sinks, 
basins or the like in operating position beneath the underside of a 
countertop. 
A still further important object of this invention is to provide an 
improved mounting system for installing kitchen sinks, vanity basins, 
drop-in stove cook tops and equivalent articles beneath an access opening 
in a countertop which is marked by improved economies of production, 
convenience of installation and dependability in use.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With initial reference to FIGS. 1-3 of the drawings, it will be recognized 
that planar countertop indicated generally at 10, is mounted horizontally 
over an undersupporting cabinet structure having parallel spaced walls 11, 
12, 13 and 14. Countertop 10 is distinguished by an enlarged generally 
rectangular shaped access opening 15 beneath which is undermount sink 16 
having a depressed or central bowl portion or area 17 formed integrally 
with a laterally extending rim flange 18 about the upper end periphery of 
bowl 17, all in conventional fashion. 
The improved mounting assembly according to this invention comprises a pair 
of elongated linear, rigid rails 20, 20 extending along opposite sides of 
the sink 16, with the ends of such rails being supported by mounting 
brackets 21, 21 affixed to a suitable support such as the opposing walls 
11, 12 of the cabinet. A plurality of vertically adjustable leveling 
devices 22, 22 for leveling sink 16 and clamping it to counter 10 are 
mounted at desired positions along the length of each of the mounting 
rails 20, 20 as will be described in great particular presently. 
While the generalities of the current invention are apparent from the 
foregoing description, specific features of the improved mounting system 
of this invention will be better understood from FIGS. 4-9 of the drawings 
and the detail description which follows. 
As best shown in FIG. 5 of the drawings, the elongated mounting rails, 
indicated generally at 20, are formed as unitary extrusions of 
substantially inverted U-shaped cross section to include a planar top wall 
30 and two depending parallel planar side walls 31 and 32 extending 
downwardly from the lateral limits of the top wall 30 and having a depth 
that is substantially equivalent to the width of top wall 30 although 
these dimensions may vary with load carrying requirements. In general, it 
is preferred that the extruded rails 20 be of lightweight aluminum, 
aluminum magnesium alloy or aluminum steel alloy capable of providing the 
desired rigidity and tensel strength required for an elongated beam in 
accordance with this invention. 
As previously noted rails 20 are designed to carry a plurality of 
selectively spaced leveling devices each of which in the illustrated case, 
constitutes a threaded bolt 33 with cooperative nut 34 (see FIG. 5). In 
order to accomplish the desired functional requirements of the rail the 
upper wall 30 thereof is periodically formed by punching or otherwise 
forming slots 35 at spaced intervals along its length which communicate 
with the interior of the inverted U-shaped configuration defined by the 
walls 30, 31 and 32 of the rail member. It further will be noted that each 
of the side walls 31 and 32 is formed with an inwardly projecting rib 36 
which extend the length of walls 31 and 32 and partially across the 
interior of the inverted U rail configuration and which are separated by a 
medially disposed elongated slot 37. This slot has a width sufficient to 
permit the free passage of the body of the bolt members 33 for the purpose 
of slidably moving nut and bolt combinations along the ribs 36 between two 
desired overdisposed openings 35, 35 of the rail member. It also will be 
noted that two opposing ribs 36, 36 are spaced below the upper wall 30 of 
the extruded rail a distance sufficient to permit the introduction of the 
nuts 34 of the bolt and nut leveling devices between the upper side of the 
ribs 36 and the bottom side of top wall 30. Thus, the bolts 33 can be 
partially threaded into a nut 34 and that combination then slidably moved 
along the opening between the ribs 36 and wall 30 to a desired location 
opposite a slotted opening 35 in the manner shown in FIG. 4, for example. 
Thereafter threaded advancement of the bolt through the nut serves to 
advance the upper end of the threaded bolt shank into engagement with 
flange 18 of the sink structure whereby the latter may be leveled and 
clamped tightly against the underside of the countertop 10, as indicated 
in FIG. 4 of the drawings. 
It also is to be noted that the two side walls 31, 32 are parallel and the 
bottom side of the rail 20 is open with no intervening wall in the zone 
between the bottom portions of walls 31 and 32 for reasons which will be 
clarified hereinafter (see FIG. 9). 
While the two rails 20 serve to hold the adjustable leveling bolts and 
cooperating nuts for the purpose of clamping the rim of the sink tightly 
to the underside of the overlying countertop, as above described, it is 
essential for the successful operation of this operation that the rails be 
amply supported and held level in stationary spaced parallel relationship 
on opposite sides of the sink, so that the upward threading action of the 
bolts 33 serve to move the sink rim uniformly into engagement with the 
countertop. This function is accomplished by means of the mounting 
brackets 21 which are engaged with the opposite ends of each of the rails 
20 to provide a reactionary platform against which the forces exerted by 
the leveling bolts are opposed. 
As shown in FIGS. 7 and 8, each of the brackets 21 comprises the elongated 
leg portion 40 having one or more openings 41 therethrough, one near the 
upper end and one near the lower end thereof for passage of appropriate 
screw fasteners. The uppermost end of the arm 40 is traversed by a right 
angularly related arm portion 43 of relatively short length having a screw 
receptive opening 44 therethrough. Extending in a opposite direction from 
the arm 43 and located at selected spaced intermediate positions along the 
length of the leg 40 are a plurality of projecting fingers 46, 46 (in this 
case two such fingers) which extend a short distance outwardly and at 
right angles to the plane of the leg 40. Like the rail 20, the brackets 21 
preferably are extruded lightweight metal cut to a desired width for 
convenience and economy of production and to maintain uniformity of 
bracket dimensions. 
As noted best in FIG. 4 of the drawings, the brackets 21 are mounted 
against the inside face of a cabinet wall, such as wall 12, or in lieu of 
such a wall a framing rail of the cabinet with the arm 43 thereof 
extending across the upper end of the wall 12 and preferably sunk in a 
rabbited socket so the upper face of the arm 43 lies flush with the upper 
edge of the wall 12 to avoid interference with full facial contact with 
the overlying countertop 10. If desired, a screw fastener may be passed 
through opening 44 of arm 43 to secure the upper end of the bracket 21 to 
the upper edge of the wall 12 with similar screw fasteners through the 
openings 41 of the leg 40 to secure the bracket in desired vertically 
extending fixed position, one at each end of the rail members 20. In most 
instances, the open bottom side of rails 20 may be placed directly over 
the selected one of the fingers 46 to rest on the internal ribs 36 in 
accordance with the depth of the sink's flange lip 18 and its thickness in 
formation. In some instances the sink lip flange is turned downwardly and 
in that instance, depending on the extent of the downturn the intermediate 
or even a lower finger may be employed. In practice it has been found that 
the presence of the two fingers 46 as shown are sufficient to meet most 
installation requirements. 
In the FIG. 4 showing of a rail 20 and bracket 21, the brackets uppermost 
finger 46 is inserted into the nut receptive channel area between the 
upper faces of the ribs 36, 36 in the underface of upper wall 30 or the 
associated rail 20. In order to accomplish such an installation, the 
selected lip 46 is first inserted into such spacing of the rail, prior to 
fastening the bracket 21 to the cabinet wall or frame rail. This is 
accomplished by accurately measuring the spacing between the supports, 
such as opposing walls, of the cabinet or the supporting frame rails, and 
cutting the mounting rail 20 to appropriate length to accommodate the 
thickness of bracket legs 40. The selected fingers 46 of the bracket are 
then inserted into the nut receiving slot at both ends of the rail. The 
entire bracket and rail assembly is then deposited within the cabinet 
space and aligned with the sides of the sink. It will be understood that 
the extending finger 43 at the upper end of the bracket serves to suspend 
the bracket from the side wall of the cabinet or frame rail, as the case 
may be. Normally a screw fastener through the opening 44 thereof will be 
sufficient to maintain the bracket in a desired position once the weight 
of the sink is transferred to the rails 20 and leveling devices 22. In the 
alternative, as above mentioned, the brackets may be positioned and 
fastened in place and the rails 20 thereafter placed over one of the 
selected fingers of the bracket means to engage the underside of the two 
ribs 36, 36. 
It is to be noted that the hereinabove described and illustrated assembly 
of this invention is particularly adapted for heavy cast metal or ceramic 
sinks and vanity basins to provide a novel mounting structure for such 
articles in fulfillment of that long felt need in the industry. 
From the foregoing it is believed that those familiar with the art will 
readily understand and appreciate the novel advancement presented by this 
invention over the prior art and will appreciate that while the same has 
herein been described in association with a preferred embodiment thereof 
illustrated in the accompanying drawings, such embodiment is susceptible 
to variation, modification and substitution of equivalents without 
departing from the spirit and scope of the invention which is intended to 
be unlimited by the foregoing description except as may appear in the 
following appended claims.