Stair stringer assembly

A stringer assembly includes a support element, a plurality of brackets and a plurality of alignment elements. The brackets are connected to the support element, and each bracket includes a rise indicator corresponding to a desired rise dimension and a run indicator corresponding to a desired run dimension. The alignment elements align the rise or run indicator on one of the brackets with the other of the rise or run indicator on an adjacent one of the brackets to space the brackets at a desired rise and run. The brackets each include a tread flange and a riser flange, such that a tread and a riser can be directly connected to each bracket. The brackets may include cutouts for a temporary tread system.

BACKGROUND OF THE INVENTION

The present invention relates to stair stringers, and more particularly to an assembly for constructing a stair stringer assembly and a stairway assembly.

Conventional stairways, especially in residential construction, include a stringer made from a 2×12 piece of wood, with portions of the stringer cut away to define the rise and run of each step. This construction requires that each triangular portion of wood removed be marked and cut separately, involving a great deal of labor and presenting numerous opportunities for error and injury—even for the most skilled carpenter. It also results in a stringer having an effective structural thickness of less than half the thickness of the original 2×12 piece of lumber, with about one-quarter of the original 2×12 piece being scrapped.

A number of attempts have been made at producing stairs more efficiently and accurately. Most of these attempts incorporate preassembled portions of stringers, portions of stairways, or complete prefabricated stairways. These products reduce some of the on-the-job calculating and cutting that is required with conventional stringers, but they also reduce, and in some cases eliminate, the ability of the installer to accommodate for variables found in the typical building environment, such as variations in the floor to ceiling height and variations in the tread and riser materials.

U.S. Pat. No. 6,088,977 discloses a plurality of L-shaped brackets that can be used to construct a stringer. Each L-shaped bracket includes markings to indicate rise and run dimensions. The stringer is constructed by separately aligning and attaching each individual bracket onto a conventional 2×6 board using the bracket's rise and run dimensions. Treads and risers are attached to the stringers to complete the stairway. This system eliminates most of the cutting issues in constructing the stringer, but suffers from disadvantages as each bracket must be carefully measured before attaching it to the 2×6 board, which increases installation time and leaves a significant potential for error in the placement of each bracket. As a result, stairway manufacturers, contractors and do-it-yourself installers are continually searching for a simple, efficient and accurate way to construct stairway stringers and stairways.

SUMMARY OF THE INVENTION

The present invention provides an assembly for accurately and efficiently constructing a stringer assembly and a stairway assembly, while providing variability during installation.

In one embodiment, the stringer assembly includes a support element, a plurality of brackets and a plurality of alignment elements. The support element may be a generally straight, structural piece, such as a 2×4. The brackets are connected to the support element, and each bracket includes a rise indicator corresponding to a desired rise dimension and a run indicator corresponding to a desired run dimension. The alignment elements register the brackets by aligning the rise indicator on each of the brackets with a run indicator on an adjacent one of the brackets to space the brackets at a desired rise and run and to square the brackets at the proper angles. The brackets each include a tread flange and a riser flange, such that a tread and a riser can be directly connected to each bracket.

In one embodiment, the bracket includes a body, tread and riser flanges extending from the body, and at least one of a rise indicator and a run indicator on the body. Each rise indicator and run indicator is positioned such that a run indicator on one bracket can be aligned with a rise indicator on a second bracket. When the brackets are aligned in this manner, they space apart the tread flange on the one bracket from the tread flange on the second bracket at a desired rise dimension and a desired run dimension. Additional brackets may be similarly aligned and attached together to form the stringer assembly. The rise indicators and run indicators may be holes defined in the body of the bracket, and in one embodiment the bracket includes a plurality of rise indicator holes and a plurality of run indicator holes, each corresponding to a desired rise dimension or a desired run dimension. The assembly may further include a head bracket capable of being attached to the ceiling and having a rise indicator and a foot bracket capable of being attached to the floor and having a run indicator. Finally, each bracket may also include a plurality of attachment holes for securing the bracket to the support element and thus transferring loads to the support element.

In another embodiment, the assembly includes a temporary tread system, wherein the bracket body includes a cutout that is sized to receive a temporary tread support. A safe and solid temporary tread can be attached to the temporary tread support for use by installers and workers during construction before the finished tread is installed on the tread flanges. In one embodiment, the body includes a cutout shaped to receive a 2×4, and the cutout is spaced from the tread flange on the bracket such that the finished tread can be attached to the tread flange without removing the temporary tread. In a stairway assembly with multiple stringers, the temporary tread support can be inserted through each stringer, and the temporary tread can be glued, nailed, screwed or otherwise attached to the temporary tread support. In addition, in one embodiment, the temporary tread support can extend through and beyond the brackets to rest on a vertical support post to aid in transferring stair loads.

In yet another embodiment, the assembly includes a preassembled tread and riser combination that can be attached to the bracket as a single piece. The riser or tread includes a notch to securely receive an end of the other piece. The tread piece attaches to the tread flange of a first bracket and the riser attaches to the riser flange of a second bracket.

The present invention provides an accurate way to create and assemble a stringer, while providing a high degree of variability to accommodate for different rises and runs, as well as normal construction variables. The rise and run indicator holes are easily aligned to provide the desired rise and run spacing while also registering each bracket with the adjacent brackets. The tread and riser flanges enable a direct connection with the treads and risers, and the temporary tread cutout allows installers to easily assemble temporary treads, without requiring additional labor to remove or replace the temporary treads before installing the finished treads. In addition, the tread and riser system securely supports the loads of the entire length of the back of the tread, which in some cases may eliminate the need for a middle stringer.

These and other objects, advantages, and features of the invention will be readily understood and appreciated by reference to the detailed description of the current embodiment and the drawings.

DETAILED DESCRIPTION OF THE CURRENT EMBODIMENTS

A stair stringer assembly according to one embodiment of the present invention is shown inFIG. 1and is generally designated10. As shown, the assembly10includes a left stringer assembly12and a right stringer assembly14. The stringer assemblies are each attached to a support board16that extends from the floor18to the upper floor structure20. In one embodiment, each stringer assembly12,14includes a plurality of brackets, including a head bracket22, a foot bracket24and a plurality of center brackets26. Each pair of brackets on opposing left12and right14stringer assemblies supports a tread28and a riser30. As shown inFIGS. 2-4, the brackets22,24and26each include at least one rise indicator21or run indicator23. As shown inFIG. 5, the rise indicator21of a first bracket can be aligned with a run indicator23of a second bracket to attach the brackets to the support board16with a desired rise and run between the treads28and risers30on each bracket.

As noted above, in one embodiment, the stairway assembly10includes two stringer assemblies12and14. The left stringer assembly12supports the left side of the stairway10and the right stringer assembly14supports the right side of the stairway10. In another, embodiment, the stairway10may include additional stringer assemblies as necessary to provide sufficient support for the stairway10. For instance, a third stringer assembly may be included to support the center of the stairway. The third stringer assembly may be a left stringer assembly, a right stringer assembly or a different central stringer assembly.

FIGS. 2-4show close-up views of the brackets22,24and26of the left stringer assembly12. In the illustrated embodiment, these brackets are mirror images of the brackets of the right stringer assembly; therefore, only the left set will be described in detail. The brackets made be formed from a variety of materials, for example, they made be made from sheet steel, aluminum, or another alloy or composite material. The bracket materials made be formed from a variety of processes, including stamping or molding.

Referring now toFIG. 2, in one embodiment, the head bracket22includes a generally planar body36having a front edge38, a rear edge40, a top edge42and a bottom edge44. As shown, the top edge42is generally perpendicular to the front edge38and the rear edge40. The front edge38is longer than the rear edge40, and the bottom edge44angles from the front edge38to the rear edge40. The head bracket22additionally includes a tread flange50, a riser flange52and a support flange54. In the illustrated embodiment, the tread flange50and riser flange52are separate pieces that are attached to the top42and front38edges by a conventional method, such as a plurality of sharp, nail-like projections (not shown) that extend from the bracket22into the flanges50,52, or other adhesives, fasteners or both. The tread50and riser52flanges may be formed from laminated wood, or they may alternatively be formed from a variety of other conventional materials. In one embodiment, the tread flange50has a length that is approximately the same size or shorter than the shortest conventional stairway run, for example, about 9 inches or less. As illustrated, the support flange54is formed with the body36as a single piece and bent approximately at a right angle to the body36. The support flange54may include a plurality of holes that are capable of receiving fasteners for attaching the support flange to the upper floor structure20. In one embodiment, shown inFIGS. 1,2and12an additional support bracket51may be provided. The support bracket51may be taller than the support flange54, such that it extends above the support flange and the top edge42of the bracket to provide extra material for attaching the support flange54and the bracket22to the upper floor structure20. In an alternative embodiment, the support flange54itself may be elongated to extend above the top edge42of the bracket.

The head bracket22additionally includes a rise indicator21. In the illustrated embodiment, the rise indicator21is a plurality of holes32defined in the body in two parallel staggered lines56and58. Each staggered line56,58starts proximate to the bottom edge44of the bracket22and extends toward the top edge42. As shown inFIG. 6, each rise indicator hole32may have a marking positioned next to it to indicate the rise dimension corresponding to the particular hole. In one embodiment, the rise indicator holes32, and thus the rise indicator markings, are positioned to provide rise dimensions ranging from 6 inches to 8⅛ inches. The holes are staggered in two columns, which may be labeled “A” and “B” respectively. The head bracket may also include a temporary tread support cutout59extending through the body36and positioned near the top edge42, but spaced from the top edge42. As discussed in more detail below, the temporary tread support cutout59is sized to receive a temporary tread support57, such as a conventional 2×4 board. Finally, the head bracket22may include additional attachment holes55at various locations on the head bracket to receive fasteners such as screws or nails for securing the bracket22to the support board16.

Referring now toFIG. 3, in the illustrated embodiment, the center bracket26is generally a right triangle in shape, although a variety of shapes are possible. As shown, the center bracket26includes a generally planar body60having a top edge62, a front edge64and a bottom edge (or hypotenuse)66. As with the head bracket22, the center bracket26includes a tread flange68and a riser flange70that are attached to the top62and front64edges of the bracket26as a separate piece. The center bracket26additionally includes a rise indicator21and a run indicator23. As shown inFIG. 3, the rise indicator is a plurality of holes72defined in the body60in two parallel staggered lines74and76. The lines74,76start proximate to the bottom edge66and extend generally parallel to the front edge64. The center bracket26may also include the rise indicator markings discussed above in connection with the head bracket22. The run indicator23is a plurality of holes78defined in the body60in two parallel lines80and82. The lines80,82start proximate to the bottom edge66and extend parallel to the top edge62. As shown inFIG. 7, each run indicator hole78may include a marking positioned next to it to indicate the run dimension corresponding to the particular hole. In one embodiment, the run indicator holes72, and thus the run indicator markings, are positioned to provide run dimensions ranging from 9 inches to 11¼ inches. As shown inFIG. 7, the markings may be located on opposing sides of the holes, with one side labeled “A” and the other side labeled “B.” In this embodiment, the markings indicate to the user that if column A is used on the rise indicator21, then the markings A should be used on the run indicator23. In one embodiment, the center bracket26may also include a temporary tread support cutout84that is similar to the temporary tread support cutout59in the head bracket22. The center bracket26, like the head bracket22, may also include attachment holes55.

Referring now toFIG. 4, in one embodiment the foot bracket24includes a generally planar body90having a top edge92, a front edge94, a bottom edge96and a rear edge98. As with the head bracket22and center bracket26, the foot bracket24includes a tread flange100and a riser flange102that are attached to the top92and front94edges of the bracket24as a separate piece. The foot bracket24additionally includes a floor flange106extending along the bottom edge96. In the illustrated embodiment, the floor flange is formed from the same piece as the body90and is bent generally at a right angle to the body90.

The foot bracket24additionally includes a run indicator23. As shown inFIG. 4, the run indicator is a plurality of holes112defined in the body90in two parallel lines114and116. The lines114,116start proximate to the rear edge98and extend generally parallel to the top edge92. The foot bracket24may include the run indicator markings discussed above in connection with the center bracket and shown inFIG. 7. In one embodiment, the foot bracket24may also include a temporary tread support cutout118that is similar to the temporary tread support cutouts59and84in the head bracket22and center bracket26. The foot bracket24may also include attachment holes55as in the head bracket22and center bracket26.

FIGS. 8-10show a second embodiment of the head bracket22′, foot bracket24′ and center bracket26′. In this embodiment, the brackets22′,24′ and26′ are substantially the same as the first embodiment of the brackets22,24and26, except that the tread flange50′, riser flange52′ and support flange54′ of the head bracket22′ are all formed with the body36′ as a single piece, by bending the flanges at right angles with the body36′ (in the direction extending out of the page inFIG. 8). Similarly, the tread flange68′ and the riser flange70′ of the center bracket26′, and the tread flange100′, riser flange102′ and floor flange106′ of the foot bracket24′ are bent from the bodies of the center26′ and foot24′ brackets respectively. In one embodiment, the brackets22′,24′ and26′ are all stamped metal products.

FIG. 12-13show an embodiment of the present invention including a combination tread and riser product200. In this embodiment, at least one tread202and at least one riser204are preassembled before attachment to the stringer assemblies12,14. As shown inFIG. 13, in one embodiment, the tread202and riser204are attached by a rabbit joint, wherein the inner edge211of the tread202may be inserted into a notch210in the front surface212of the riser204. In this embodiment, the preassembled tread and riser combination provides additional structural support for the entire back and underside of the staircase, which may enable construction of staircases with only two stringers. In another embodiment, the treads and risers may be attached in the reverse manner, with a notch in the lower surface208of the tread that receives the upper edge205of the riser.

Assembly of the stairway10of the illustrated embodiment begins with measuring the distance from the floor18to the upper floor structure20, and then calculating or determining the number of brackets, including a head bracket22, a foot bracket24and one or more center brackets26, necessary for each stringer assembly12,14to span the distance between the head bracket22and foot bracket24. This division also determines the consistent riser height for all of the brackets22,24and26. This division may otherwise be determined by a chart that is provided with the assembly10. The desired run length can be determined from the various run lengths provided in the run indicator markings shown inFIG. 7.

One assembly method of a stringer assembly12or14begins with marking a scribe line11on a support board16. The scribe line11may be a pencil line extending substantially parallel to the longitudinal length of the support board16. In one embodiment, wherein the support board is a conventional 2×4, the scribe line11may be located about 2½ inches from the bottom edge120of the board16. In one embodiment, a center bracket26is then attached to the support board16using fasteners, such as screws or nails, extending through the attachment holes55on the bracket26and into the support board16, while aligning one of the rise indicator holes72and one of the run indicator holes78with the scribe line11, so that the bracket26is about one foot from the “foot” end121of the support board16.

In one embodiment, a foot bracket24is then attached by inserting fasteners through the run indicator holes112on the foot bracket24corresponding to the predetermined run for the stairway and into the rise indicator holes72on the center bracket26. In the illustrated embodiment (shown inFIG. 5), a first fastener is inserted through a run indicator hole112on line114and a rise indicator hole72on line74and into the support board16along the scribe line11, and a second fastener is inserted through a run indicator hole112on line116and a rise indicator hole72on line76and into the support board16along the scribe line11. Additional fasteners are inserted through the attachment holes55on the foot bracket24and into the support board16to secure the foot bracket24to the support board16.

The rest of the center panels26are then added to the initial center panel26by using the rise and run indicator markings to align the run indicator holes78of a first center panel26with the rise indicator holes72of a second center panel26and extending fasteners through the aligned holes and into the support board16along the scribe line. For instance, one fastener may be inserted through a rise indicator hole72on line74on a first bracket26and through a run indicator hole78on line80of a second bracket26, and a second fastener may be inserted through a rise indicator hole72on line76of the first bracket26and through a run indicator hole78on line82of the second bracket26. At any point during this process, the stringer assembly can be checked for mistakes by ensuring that each of the fasteners that extends through the aligned indicator holes72,78is also inserted along the scribe line11on the support board16. Each center bracket26can be securely attached to the support board16by inserting additional fasteners through the attachment holes55, which helps to transfer loads from the brackets26to the support board16.

The head bracket22is aligned on the support board16by aligning the rise indicator holes32on the head bracket22with the run indicator holes78on the upper-most center bracket26. In one embodiment, shown inFIG. 5, one fastener103is inserted through one of the rise indicator holes32on line56and one of the run indicator holes78on line80and into the support board16along the scribe line11, a second fastener105is inserted through one of the run indicator holes32on line58and one of the run indicator holes78on line82and into the support board along the scribe line11. Additional fasteners107may be inserted through the attachment holes55in the head bracket22to further secure the head bracket22to the support board16.

In one embodiment, after the head bracket22is secured, the portion of the support board16that extends beyond the upper edge42of the head bracket22can be cut off. Similarly, after the foot bracket24is secured to the support board16, the portion of the support board16below the bottom edge96of the foot bracket24can be cut off.

The assembled stringer assembly12or14is secured to the ceiling and floor by inserting fasteners through the support flange54and into the upper floor structure20(i.e. a hanger board, furr blocking or another ceiling support) with the tread flange50on the head bracket22spaced from the ceiling (not shown) at the predetermined rise distance. The floor flange106of the floor bracket24is attached to the floor18, or a furr block (not shown) secured to the floor18. The above-noted method may be duplicated for the opposite stringer assembly12,14and any additional stringer assemblies. Treads28may then be attached to the tread flanges50,68and100of the brackets22,24and26, and risers30may be attached to the riser flanges52,70and102of the brackets22,24and26to complete the stairway assembly. In the bracket embodiment shown inFIGS. 8-11, the treads28and risers30are attached directly to the tread flanges50′,70′ and100′ and the riser flanges52′,70′ and102′ with conventional fasteners101.

In another embodiment, wherein the brackets22,24and26include temporary tread support cutouts59,84and118, temporary treads may be installed before installation of the treads28and risers30. In this embodiment (seeFIGS. 1 and 11), temporary tread supports57are inserted through the cutouts59,84and118in each of the stringer assemblies, and temporary treads150are attached to the temporary tread supports57by conventional fasteners. Support blocks25may be attached to the temporary tread supports57to provide additional support for the temporary treads150. The temporary treads150may be used throughout the construction project to avoid damaging the finished treads28and risers30, and because the temporary tread support cutouts58,84and118and temporary tread supports57are spaced from the upper edges42,62and92and front edges38,64and94of the brackets22,24and26, the finished treads39and risers28can be installed without removing the temporary treads150. Referring toFIG. 1, in one embodiment, the temporary tread supports57may enhance the structural support of the stairway assembly by extending beyond the brackets26and onto vertical support members152.

Referring now toFIGS. 12-13, the combination tread and riser product200may be attached directly to the tread flanges50,70and100and riser flanges52,70and102. In the tread/riser combination embodiment shown inFIG. 12, including a notch210in the front surface212of the riser204, the assembly would begin with the bottom tread30(on the foot bracket24) and proceed up the stairway. One additional tread and riser combination could be split apart to add the bottom-most riser204and the top-most tread202.

Although the above-described assembly method includes a particular order for assembling the stringer assemblies12,14and stairway10, the assembly does not require a particular order. For instance, the brackets22,24and26can be attached to the support board16in any order, as long as the rise indicator holes of a first bracket are aligned with the run indicator holes of a second bracket and the scribe line on the support board16. In addition, alternative run indicators and rise indicators may be used to align the brackets. For instance, the indicators could be elongated slots, dimples, or other markings on the brackets that enable alignment of a particular rise or run dimension on one bracket with a particular rise or run dimension on another bracket. Further, although the illustrated embodiment shows the rise and run indicators being aligned by fasteners, they could otherwise be aligned with alternative alignment elements that align the rise and run indicators but do not extend into the support board.