# Patent

## Title
One-piece injection molded door sill assembly

## Abstract

A sill assembly includes an integral sill assembly having a sill base and an inclined threshold. The sill base is overmolded in an injection molding process onto the inclined threshold. A rail assembly is adjustably secured to the sill base.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY
The present application is a divisional of application Ser. No. 10/974,966, filed Oct. 28, 2004, now U.S. Pat. No. 7,536,833 the disclosure of which is incorporated by reference and to which priority is claimed.


BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to threshold and door sill assemblies for use in door jam assemblies. In particular, the present invention relates to a molded door sill assembly having a threshold formed therewith.
2. Description of Related Art
Known threshold and door sill assemblies typically include multiple components such as a sill base, an inclined tread, and a threshold. These multiple components are typically constructed separately from one another and then secured to one another in a suitable manner to form the threshold and door sill assembly. Thus, known threshold and door sill assemblies are manufactured from several parts that require a highly structured assembly and installation process.
The present invention provides improvements over known threshold and door sill assemblies to simplify the manufacturing process, reduce the number of parts, and simplify the assembly and installation process. Furthermore, the present invention provides increased protection against moisture penetration and rot.
SUMMARY OF THE INVENTION
One aspect of the invention relates to a threshold and door sill assembly that includes a sill assembly formed by an injection molding process. This aspect of the invention provides a threshold and door sill assembly including a sill assembly having a sill base that is molded to an inclined threshold. The sill base is constructed of one material that is overmolded in an injection molding process onto the inclined threshold constructed of a second material to form an integral molded sill assembly. The sill assembly is configured to receive various sill components including but not limited to an adjustable rail assembly. The rail assembly is adjustably secured to the sill base.
Another aspect of the invention relates to a door sill assembly having a sill base, jamb supports, and an inclined threshold. This aspect of the invention provides a sill assembly for a doorjamb assembly, wherein the doorjamb assembly includes a pair of vertically extending jamb members, a header structure, and at least one door. The threshold and door sill assembly includes a molded sill assembly having a sill base and an inclined threshold. The sill base is constructed of one material that is overmolded in an injection molding process onto the inclined threshold constructed of a second material to form the molded integral sill assembly. The threshold was previously formed by, for example, an extrusion process. The threshold and door sill assembly can include a pair of jamb supports. One of the jamb supports is provided on one end of the sill base and the other of the jamb supports is provided on the opposite end of the sill base. The jamb supports protrude outwardly from the opposing ends of the sill base for engaging and supporting respective jamb members. The jamb supports provide a raised platform for the jamb members to protect against rot an moisture penetration. An adjustable rail assembly and other components are secured to the sill base.
Still another aspect of the invention relates to a method of forming a threshold and door sill assembly. This aspect of the invention provides a method of forming a threshold and door sill assembly for a door jamb assembly, wherein the door jamb assembly includes a pair of vertically extending jamb members, a header structure, and at least one door. The sill assembly includes a sill base that is injection molded around an inclined threshold, the sill base being constructed of one material that is overmolded in the injection molding process onto the inclined threshold constructed of a second material to form an integral sill assembly.
Other aspects, features, and advantages of this invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, the principles of this invention.



BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings facilitate an understanding of the various embodiments of this invention. In such drawings:
FIG. 1 is a front view of an embodiment of a doorjamb assembly incorporating a sill assembly constructed in accordance with an embodiment of the invention;
FIG. 2 is a perspective view of the threshold and door sill assembly constructed in accordance with an embodiment of the invention;
FIG. 3 is a top view of the sill assembly shown in FIG. 2;
FIG. 4 is a front view of the sill assembly shown in FIG. 2;
FIG. 5 is a bottom view of the sill assembly shown in FIG. 2;
FIG. 6 is an enlarged perspective view of the sill assembly shown in FIG. 2;
FIG. 7 is a side view of an inclined threshold of the sill assembly, shown in FIG. 2;
FIG. 8 is a top view of the sill assembly shown in FIG. 2, wherein the adjustable rail assembly is removed to illustrate the rail assembly mounting structure;
FIG. 9 is an end view of the sill assembly shown in FIG. 8;
FIG. 10 is a rear view of the sill assembly shown in FIG. 8 adjacent one end of the sill assembly;
FIG. 11 is a cross-sectional view through line 11-11 of FIG. 8;
FIG. 12 is a cross-sectional view through line 12-12 of FIG. 8;
FIG. 13 is an enlarged bottom perspective view of the sill assembly shown in FIG. 2;
FIG. 14 is a side view of a rail assembly of the sill assembly shown in FIG. 2;
FIG. 15 is a cross-sectional view through line 15-15 of FIG. 14;
FIG. 16 is a cross-sectional view through line 15-15 of FIG. 14, with the fastener removed;
FIG. 17 is a side view of a rear trim piece for the sill assembly shown in FIG. 2;
FIG. 18 is a rear view of the trim piece shown in FIG. 17;
FIG. 19 is a perspective view of a jam support extension aligned with an associated jam support for use on a molded sill assembly having an extended threshold;
FIG. 20 is a perspective view of a jam support extension of FIG. 19 connected to the associated jam support; and
FIG. 21 is another embodiment of a door sill assembly.



DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS
FIG. 1 illustrates a door jamb assembly 10 incorporating a sill assembly 12 constructed according to an embodiment of the present invention. The door jamb assembly 10 includes a pair of vertically extending horizontally spaced jamb members 14, which are typically formed from wood, a horizontally extending header structure 16, which is also typically formed from wood, and at least one door 18. The sill assembly 12 includes an elongated sill assembly 20 that is connected at opposing ends to lower ends of the pair of vertically extending jamb members 14. The pair of jamb members 14, the header structure 16, and the sill assembly 12 form a generally rectangular door jamb opening within which the at least one door 18 is disposed.
The sill assembly 12 is not limited to use with the specific configuration of door jamb assembly shown and other various configurations are contemplated, for example, a doorjamb assembly may include a pair of doors, sliding door panel, a combination of fixed and movable door panels and any combination of side panels including side panels disposed on one or both sides of the door. To accommodate the placement and support of side panels, the doorjamb assembly may include one or more vertically extending mullions, which are connected at upper ends thereof to the header structure and at lower ends thereof to the threshold and door sill assembly 12 through a mullion boot assembly. Various arrangements and components are disclosed, for example, in U.S. patent application Ser. No. 10/673,639, entitled “Adjustable Rail Assembly And Components For The Same,” the disclosure of which is incorporated herein specifically by reference.
In the illustrated embodiment, the sill assembly 12 includes a sill assembly 20 and a rail assembly 22 adjustably secured to the sill assembly 20. The sill assembly 20 is formed in one-piece by an injection molding process so as to simplify the manufacturing process, reduce the number of parts, and simplify the assembly and installation process.
As shown in FIGS. 2-6, the sill assembly 20 includes a sill base 24, and an inclined threshold 26. The sill assembly may also include a pair of jamb supports 28 (also referred to as corner keys). The jamb supports 28 can be integrally molded with the sill base 24 or formed as separate components. One of the jamb supports 28 is provided on one end of the sill base 24 and the other of the jamb supports 28 is provided on the opposite end of the sill base 24. The jamb supports 28 protrude outwardly from the sill base 24 for engaging and supporting respective jamb members 14. The jamb supports 28 or corner keys elevate the jamb members 14 above the sill assembly 20, which reduces moisture penetration and rot.
The inclined threshold 26 is overmolded with the sill base 24 by an injection molding process to provide a one-piece sill assembly 20. In the illustrated embodiment, the jamb supports 28 are formed in one-piece in the injection molding process along with the sill base 24 and the inclined threshold 26.
The rail assembly 22, shown in greater detail in FIGS. 14-16, is attached with fasteners to the sill assembly 20 through tapped holes 52 provided in the sill base 24. The tapped holes 52 are preferably formed in the sill base 24 during the injection molding process. Although it is also contemplated that the holes 52 may be formed in a separate machining operation.
The one-piece injection molded sill assembly 20 will now be described in greater detail. As shown in FIG. 7, the inclined threshold 26 is preferably formed as a one-piece extrusion from aluminum or other suitable material. It is also contemplated that the threshold 26 may by formed from plastic or fiberglass. The threshold 26 includes an inclined top surface 30 that extends rearwardly from a forward edge to an upwardly extending lip structure 32. The upwardly extending lip structure 32 projects above the inclined top surface 30.
The inclined threshold 26 includes a leading edge portion 34 that extends downwardly from the forward edge thereof. The leading edge portion 34 provides a support member 38 that engages the floor in use to support the forward edge of the threshold 26. It is contemplated that the threshold 26 can be either a low threshold for a low profile sill assembly or a threshold for a high profile threshold sill assembly. Additionally, the threshold 26 can have an increased width to permit wheelchair use.
The threshold 26 includes a plurality of downwardly projecting extensions 40 (e.g., three extensions). The extensions 40 are provided to interconnect the threshold 26 with the sill base 24 during the overmolding process. The extensions 40 extend generally parallel to each other in the longitudinal direction. One or more extensions 40 are contemplated.
As shown in FIGS. 5 and 8-13, the sill base 24 extends the length of the sill assembly 20. As best shown in FIGS. 5, 11, 12, and 13, the sill base 24 includes end walls 42, at least one intermediate wall 44, and a plurality of transverse reinforcing walls 46 that increase the over all strength and stability of the sill base 24. Moreover, when the sill base 24 is overmolded onto the threshold 26, the reinforcing walls 46 are overmolded or interconnected with a corresponding extension 40 provided on the threshold 26 (see FIG. 12). Thus, the spacing between reinforcing walls 46 corresponds with the spacing between extensions 40 on the threshold 26. As shown in FIG. 12, for example, the end walls 42 and intermediate wall 44 are also interconnected with the extensions 40, which increase the stability and strength of the sill assembly 20.
The sill base 24 is preferably formed of a non-rot synthetic material, e.g., polymeric or composite material. Thus, the sill base 24 is constructed of one material, e.g., synthetic, that is overmolded onto the threshold 26 that is constructed of a second material, e.g., aluminum, to form the one-piece sill assembly 20. However, it is contemplated that the sill base 24 and threshold 26 may be formed of similar materials and molded as a single unit. With such an arrangement, the number of walls 44 and 46 may be increased to improve the rigidity of the sill assembly.
The lip structure 32 of the threshold 26 forms one side of a channel 48 that extends along the length of the sill base 24. An opposite side of the channel 48 is formed from an upwardly extending rear portion 50 provided on the sill base 24. A plurality of tapped holes 52 are provided in the channel 48 of the sill base 24 for securing the rail assembly 22. The tapped holes 52 may be formed in the sill base 24. during the injection molding process or may be formed in a separate machining operation. Also, the upwardly extending rear portion 50 has an attachment structure 54 formed thereon for securing a trim piece 76, as will be further discussed below.
In the illustrated embodiment the vertically extending jamb members 14 are connected to the sill assembly 20 by directly securing the vertically extending jamb members 14 to the jamb supports 28 provided on the sill assembly 20. As best shown in FIGS. 6 and 9-12, each jamb support 28 or corner key includes a substantially flat jamb support surface 56 that forms a base upon which the corresponding vertically extending jamb member 14 rests. The jamb supports 28 raise the jamb members 14 above the top surface 30 of the threshold 26 such that it is not in contact with any water that is standing or draining off the top surface 30. This arrangement reduces exposure of the end grain of the jamb members 14 to moisture and enhances rot prevention. The jam supports 28 also minimize damage to the bottom of the jamb members 14 during transportation. A seal assembly, e.g., gasket, may be located between the support surface 56 and corresponding jamb member 14.
The jamb support surface 56 includes a plurality of upwardly extending support flanges that are structured to engage the corresponding jamb member 14 and prevent lateral movement of the same on the jamb support 28. As best shown in FIGS. 6 and 8-10, a first rib 58 extends upwardly from an edge of the support surface 56 and a second rib 60 is laterally spaced from the first rib 58 along the edge. Opposite the first rib 58 is a corner rib 62 that extends upwardly from adjacent edges. An opening 64 is provided in the portion of the jamb supports 28 that extends over the top surface 30 to permit drainage of any water that might collect on the surface 56. This moisture then drains down the top surface 30.
The jamb supports 28 are secured to respective jamb members 14 by a plurality of fasteners. In the illustrated embodiment, a pair of openings 66 (see FIGS. 2, 3, and 5) are provided through the support surface 56 that allow fasteners to extend therethrough and into the respective jamb member 14.
The jamb supports 28 also have an interlocking structure 68 formed therewith that allows the jam supports 28 to interlock with a jam support extension 88, as will be further discussed.
An advantage of the integral jamb supports 28 is that they eliminate a critical machining operation. That is, the jamb members 14 only need a square cut on the bottom thereof in order to accommodate the jamb supports 28. This simplifies modifications for shorter doors and improves quality control.
In the illustrated embodiment, the sill base 24 and jamb supports 28 are preferably formed of a synthetic material. It is noted that a synthetic material is preferable, since this type of material is generally resistant to decay or other degradation. For example, water cannot travel up the jamb supports 28 and into the jamb members 14 to cause rot.
FIGS. 14-16 illustrate the rail assembly 22. The rail assembly 22 is secured to the sill assembly 20 to close or eliminate any gap between the sill assembly 20 and the bottom of the door 18. The height of the rail assembly 22 may be adjusted to ensure a good seal with the sweep on the bottom of the door 18.
As shown in FIGS. 14-16, rail assembly 22 includes a rail member 70 and a plurality of adjustment bolts 72 and associated washers 74. The rail member 70 is preferably formed from an extruded plastic material, e.g., PVC. The rail member is 70 adapted to be received within the channel 48 of the sill base 24 such that an upper portion of the rail member 70 extends past or adjacent to the lip structure 32 and the upwardly extending portion 50 of the sill base 24. The adjustment bolts 72 secure the rail member 70 to the sill base 24. Specifically, the adjustment bolts 72 are received within a corresponding tapped hole 52 provided within the channel 48 of the sill base 24. Rotation of the bolts 72 with respect to the sill base 24 can raise and lower the rail member 70 with respect to the sill assembly 20. The rail assembly 22 is capable of vertical but not lateral movement.
FIGS. 17 and 18 illustrated a contoured trim piece 76 that may be fastened to a rear end portion of the sill assembly 20 to cover the rear side of the channel 48 and for aesthetics. The trim piece 76 has an exposed surface 78 that faces the interior of the building. In the illustrated embodiment, the trim piece 76 is fastened to the sill assembly 20 with a snap-fit. Specifically, the trim piece 76 has upper and lower hook portions 80, 82. As noted above, the upwardly extending portion 50 of the sill base 24 has an attachment structure 54 with upper and lower recessed portions 84, 86 (see FIGS. 11 and 12). The lower hook portion 82 of the trim piece 76 is first engaged with the lower recessed portion 86 of the attachment structure 54, and then the upper hook portion 80 is engaged with a snap-fit with the upper recessed portion 84 to secure the trim piece 76 to the attachment structure 54. However, the trim piece 76 may be secured to the sill base 24 in any other suitable manner.
FIGS. 19 and 20 illustrate a jamb support extension 88 that may be connected with an associated jamb support 28. FIGS. 19 and 20 illustrate another embodiment of a jamb support 228. However, it should be understood that the jamb support extension 88 may be utilized with either jamb support 28, 228 in a similar manner. The jamb support 228 is substantially similar to the jamb support 28 described above and is indicated with similar reference numerals. In contrast, the jamb support 228 does not include the opening 64 and the jamb support 228 has a different outer side wall structure 290. Additionally, the jamb support 228 includes a 292 notch for accepting a weatherstrip therein.
As noted above, the jamb supports 28, 228 have an interlocking structure 68, in the form of a recess, formed therewith. The jamb support extension 88 has an interlocking structure 94, in the form of an extension, formed therewith. In use, the extension of the jamb support extension 88 is inserted into the recess of the jamb support 28, 228 to interlock the jamb support extension 88 with the jamb support 28, 228 in cooperating relation. The jamb support extension 88 allows the sill assembly 20 to accommodate wider door jambs 14 and/or wider thresholds 26. Accordingly, the jamb support extension 88 includes a substantially flat jamb support surface 96 that is flush with the support surface 56 in use. The jamb support extension 88 also includes an openings 98 that allows a fastener to extend therethrough and into the respective jamb member 14. Additionally, the jamb support extension 88 includes seal members 100 that overlap the jamb support 28, 228 in use to seal the edges between the jamb support extension 88 and the jam support 28, 228. The jamb support extension 88 may be formed with a similar material and by a similar process, e.g., molding, as the jamb supports 28, 228.
In the illustrated embodiment, the sill assembly 20 has a high profile. However, the sill assembly 20 may be suitably modified to provide a low profile wherein the overall height is lower than that of the high profile sill assembly.
FIG. 21 illustrates another embodiment of a threshold and door sill assembly 312 having a one-piece sill assembly 320. As illustrated, jamb support extensions 388 are connected to respective jamb supports 328 of the sill assembly 320. Additionally, the rear end of the sill assembly 320 is structured to accommodate a wide range of doors, including for example sliding doors.
It can thus be appreciated that the aspects of the present invention have been fully and effectively accomplished. The foregoing specific embodiments have been provided to illustrate the structural and functional principles of the present invention, and are not intended to be limiting. To the contrary, the present invention is intended to encompass all modifications, alterations, and substitutions within the spirit and scope of the appended claims.

## Claims

1. A method of forming a threshold and door sill assembly for a door jamb assembly, wherein the door jamb assembly includes a pair of vertically extending jamb members, a header structure, and at least one door, the method comprising:
forming a threshold;
forming a sill assembly including a sill base by an injection molding process, wherein the sill base is overmolded in the injection molding process onto the threshold;
adjustably securing a rail assembly to the sill base;
forming a pair of jamb supports, one of the jamb supports being provided on one end of the sill base and the other of the jamb supports being provided on an opposite end of the sill base, wherein the jamb supports protrude outwardly from the sill base for engaging and supporting a respective one of the jamb members;
forming a pair of jamb support extensions; and
interlocking each of the jamb support extensions with a respective jamb support, the jamb support extensions allowing the sill assembly to accommodate at least one of a wider door jamb member and wider threshold.

2. A method according to claim 1, further comprising:
forming the jamb supports in one-piece in the injection molding process along with the sill assembly.

3. A method according to claim 1, further comprising forming a plurality of holes in the sill base during the injection molding process for securing the rail assembly.

4. A method according to claim 1, further comprising forming each jamb support extension to include a seal which overlaps the respective jamb support.

5. A method according to claim 1, wherein the jamb support and the jamb support extensions removably interlock with each other.

6. A method according to claim 1, further comprising forming the threshold to include an upwardly extending lip and forming the sill base to include an upwardly extending portion, the lip and the upwardly extending portion forming a channel to receive the rail assembly.

7. A method according to claim 1, further comprising forming the sill base to include a first end wall, a second end wall, and at least one intermediate wall and forming the threshold to include at least on extending projection.

8. A method according to claim 7, further comprising forming the sill base to include at least one reinforcing wall, said reinforcing wall positioned so that it mates with the extending projection.

9. A method according to claim 1, further comprising forming a trim piece to be attached to the back of the sill base.

10. A method according to claim 9, wherein the trim piece is snap-fit to the sill base.

11. A method according to claim 1, further comprising forming the threshold from aluminum and forming the sill base from a polymeric material.

12. A method according to claim 1, wherein the threshold comprises at least one downwardly projecting extension.

13. A method of forming a threshold and door sill assembly for a door jamb assembly, wherein the door jamb assembly includes a pair of vertically extending jamb members, a header structure, and at least one door, the method comprising:
forming a threshold;
forming, by an injection molding process, a sill assembly comprising a sill base and a pair of jamb support members, each jamb support member comprising a support surface and at least one support flange extending from said support surface, wherein the sill assembly is overmolded in the injection molding process onto the threshold;
adjustably securing a rail assembly to the sill base;
forming a pair of jamb support extensions; and
interlocking each of the jamb support extensions with a respective jamb support, the jamb support extensions allowing the sill assembly to accommodate at least one of a wider door jamb member and wider threshold.

14. A method according to claim 13, further comprising forming the jamb supports to include a first flange, a second flange laterally spaced from said first flange, and a corner flange extending from the support surface.

15. A method according to claim 13, further comprising forming the jamb supports so that the support surface is above the threshold.

16. A method according to claim 13, further comprising forming an opening in the jamb supports to permit water drainage from the support surface.

17. A method according to claim 13, wherein the jamb support and the jamb support extensions are formed to removably interlock with each other.

18. A method according to claim 17, further comprising forming each jamb support extension to include a seal which overlaps the respective jamb support.

19. A method according to claim 13, wherein the threshold comprises at least one downwardly projecting extension.