CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. provisional patent application No. 63/322,343, filed on March 22, 2022, and which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention concerns a construction site staircase assembly and method for installing the same. The construction staircase is essentially supported by adjacent posts using stringer anchors, and typically includes a stairwell frame connected to the posts to secure the staircase to the stairwell extending through the upper floor. The different pieces /modules of the assembly are all entirely prefabricated /manufactured and adjusted in factory before shipping and assembled on site.

BACKGROUND OF THE INVENTION

[0003] There are currently no construction site staircase including a stairwell that are not fully manufactured in the factory, with no measurement taken on site. In fact, for years and years (if not centuries), all safe staircases on a construction site which follow certain construction rules are usually fabricated and built on-site. This is expensive, while requiring that the staircase professional shows up a few times on the construction site to take required measurements, usually after the floor specialist (contractor) had first made a stairwell cavity size through the upper floor to the best of his knowledge without any measurement provided on drawings/plans from the architect, and depending on the actual beams being used to built the floor. Accordingly, the staircase is therefore built around the stairwell pre-manufactured on its own. [0004] This is usually cumbersome, while being expensive to the owner since the staircase has to be finished up on site by having the professional carpenter and woodworker sizing and cutting different parts. This way of manufacturing staircases is not efficient, and ends up generating al significant amount of garbage, especially when the construction site stairwell assembly has to be dismantled to allow for a finished staircase to be manufacture and installed there after at the same location. The stair manufacturer also has to be located at an acceptable distance from the construction site as his presence is required a few times, thereby limiting the choice of staircases and/or staircase manufacturers, especially for ‘normal’ buyers who cannot afford luxury and/or custom-made staircases, proposed by only a few manufacturers.

[0005] This way of fabricating and installing a staircase could be found to be similar than if a door has to be sized and manufactured and installed on site after a corresponding door frame has been made independently, which is absolutely not professional and cost-effective.

[0006] Accordingly, there is a need for an improved staircase assembly and method of installation therefor.

SUMMARY OF THE INVENTION

[0007] It is therefore a general object of the present invention to provide an improved staircase assembly and method of installation therefor that obviates at least some or all of the above-mentioned drawbacks.

[0008] An advantage of the present invention is that the construction staircase assembly, which preferably includes staircase modules, staircase posts and a stairwell frame or module, is fully manufactured (prefabricated) in the factory, with no measurement taken on site, as standardized (predetermined selected) stairwell sizes could be used and shown by the architect in the building plans, as well as other measurements such as the exact vertical distance between the successive floors, to allow determining the required number and sizes of each step as well as the overall dimensions of the staircase. All components of the present invention are cut and adjusted in the factory. All modules of the construction staircase assembly, namely the construction staircase modules (each straight or angle portion) and the stairwell frame and railing assembly, are delivered to the construction site ready for installation.

[0009] Another advantage of the present invention is that it permits the approval of all components of the construction staircase and the stairwell, thus ensuring the safety of the construction sites, and, by being entirely manufactured in factory the staircase assembly of the present invention, including a stairwell frame, allows for standardization of the stairs.

[0010] Other advantages of the present invention are as follows:

Elimination of any measurement taken on the construction site, since all dimensions are determined construction details from the architect’s floor plans or drawings;

Enablement of a standardization of staircases, as well as corresponding certification (according to local construction code or the like);

- All components of the modules of the staircase assembly are entirely manufactured in factory and elimination of any adjustment and/or cutting of parts on site;

Increase of on-site security of workers;

- The staircase, the stairwell, the railings being installed at the same time as the beams at the beginning of the construction, this makes it possible to secure the opening in the floor from the beginning of the construction;

- The present invention eliminates the use of scales that causes accidents;

- Since there is no required cutting to be made in the stringers, the construction site staircase automatically adjusts to a proper horizontal and vertical levelling of the treads (at right angle); a specially designed hardware allows this adjustment;

It is an environmentally friendly (eco-responsible) product because the structure is made of metallic, aluminum, and/or wooden parts, all reusable; - The customer is completely satisfied because he chooses absolutely everything according to his budget, his tastes, etc.; and

- All the parts of the invention are reusable, making the staircase assembly environmentally friendly, especially when the construction staircase has to be removed in the case it is replaced by another finished staircase;

- The construction staircase assembly (at least the stairwell frame, staircase posts, and possibly the staircase) typically remains installed and is subsequently covered with a finished staircase assembly, while defining the location of the different walls of the stairwell. To this end, all parts, such as the stringer anchors provide for the spacing to subsequently receive a finishing wall, if required.

[0011] A further advantage of the present invention is that the construction staircase assembly, and the method of assembly thereof, increases the production on site (building construction), reduces costs and losses (discarding) of material, increases profitability, brings new specialized or skilled labour, and increases the customer base of the manufacturers.

[0012] In a first aspect, the present invention provides a staircase assembly for assembling on a construction site of a building between upper and lower floors, the upper floor having an opening extending therethrough and defining a stairwell, the staircase assembly comprising:

- a plurality of posts extending between the upper and lower floors and being connected thereto;

- stringer anchors attaching to at least two of the plurality of posts;

- two stringers positioned parallel to and spaced from each other, at least one of the two stringers mounting on the stringer anchors;

- a plurality of treads equally spaced from one another and positioned along the two stringers; each said tread defining a rear side attaching to the two stringers via a respective rear tread attachment and a front side securably connecting to the rear side of a frontward adjacent one said tread via a front tread attachment; - for each said tread, the rear tread attachment being slidably adjustably positioned along the two stringers and allowing angular pivoting adjustment of the tread relative to the two stringers about a pivoting axis generally perpendicular to the two stringers; and

- for at least each said tread but a frontward most said tread, the front tread attachment being adjustable in length to allow adjustment of a height between the two adjacent said treads connected thereto thereby ensuring a horizontal levelling of the tread.

[0013] In one embodiment, the staircase assembly further includes a stairwell frame adapted to be installed on the upper floor at a perimeter of the stairwell, the stairwell frame including a plurality of stairwell beams positioned in an end- to-end configuration along the perimeter, at least one said stairwell beam having a lower ledger strip facing downward toward the lower floor mounted there under, at least one said post connecting to the lower ledger strip.

[0014] Conveniently, the lower ledger strip includes a lower channel extending there along to allow for a lengthwise adjustable positioning of the at least one said post there along.

[0015] Conveniently, the staircase assembly further includes a railing assembly having railing posts supporting a railing handrail, at least one said stairwell beam having an upper ledger strip facing upward opposite the lower ledger strip and away from the lower floor mounted thereon, the railing posts mounting on the upper ledger strip.

[0016] Conveniently, the railing assembly further includes at least one transversal retaining bar mounting on at least two of the railing posts.

[0017] Conveniently, the upper ledger strip includes an upper channel extending there along to allow for a lengthwise adjustable positioning of the railing posts there along.

[0018] In one embodiment, the at least one of the two stringers includes a plurality of transverse slots extending there through and generally parallel to one another, each said transverse slot receiving a respective stringer anchor therein.

[0019] In one embodiment, the at least one of the two stringers has a top portion slidably receiving the rear tread attachment of each said tread there along.

[0020] Conveniently, the rear tread attachment includes a lower jaw body slidable along the top portion and clamping there onto at a predetermined position.

[0021] Conveniently, the rear tread attachment includes an upper protrusion with a stem-mounted cylindrically rounded tip movably mating with and supporting thereon a corresponding slotted blind cavity extending into the rear side of the tread.

[0022] In one embodiment, the front tread attachment includes top and bottom end parts connected to one another with an adjustable longitudinal attachment member, the top and bottom end parts securing to the front side of the tread and the rear side of the frontward adjacent one said tread, respectively.

[0023] Conveniently, the adjustable longitudinal attachment member includes a threaded rod connecting to corresponding threaded holes extending into the top and bottom end parts.

[0024] In one embodiment, the front tread attachment of the frontward most said tread being a frontward most riser attaching thereto and connectable to the lower floor.

[0025] In one embodiment, the railing assembly further includes an angle tread frame structure mounting on frame anchors attached to selected ones of the plurality of posts, and a plurality of angle treads mounting on the angle tread frame structure.

[0026] Conveniently, a lowermost said angle tread having a front side thereof securably connecting to the rear side of a frontward adjacent one said tread via a corresponding one said front tread attachment. [0027] Conveniently, an uppermost said angle tread having a rear side thereof securably connecting to the front side of a rearward adjacent one said tread via a corresponding one said front tread attachment.

[0028] In one embodiment, the railing assembly further includes a stair handrail connecting to the at least two of the plurality of posts and being positioned between the at least one of the two stringers and the upper floor.

[0029] In another aspect, the present invention provides a method for assembling a staircase assembly on a construction site of a building between upper and lower floors, the upper floor having an opening extending therethrough and defining a stairwell, the method comprising the steps of:

- connecting a plurality of posts extending between the upper and lower floors to the upper and lower floors;

- attaching stringer anchors to at least two of the plurality of posts;

- positioning two stringers parallel to and spaced from each other, and mounting at least one of the two stringers on the stringer anchors; and

- positioning a plurality of treads equally spaced from one another along the two stringers by attaching a rear side of each said tread to the two stringers via a respective rear tread attachment being slidably adjustably positioned along the two stringers and allowing angular pivoting adjustment of the tread relative to the two stringers about a pivoting axis generally perpendicular to the two stringers, and by securably connecting a front side of at least each said tread but a frontward most said tread to the rear side of a frontward adjacent one said tread via a front tread attachment being adjustable in length to allow adjustment of a height between the two adjacent said treads connected thereto thereby ensuring a horizontal levelling of the tread.

[0030] In one embodiment, the step of connecting a plurality of posts includes the steps of:

- installing a stairwell frame on the upper floor at a perimeter of the stairwell by positioning a plurality of stairwell beams of the stairwell frame in an end- to-end configuration along the perimeter; and - connecting at least one said post to a lower ledger strip facing downward toward the lower floor and mounted under at least one said stairwell beam.

[0031] Conveniently, the step of connecting at least one said post includes the step of connecting the at least one said post to the lower ledger strip by adjustably positioning the at least one said post lengthwise along a lower channel extending along the lower ledger strip.

[0032] In one embodiment, the method further includes the step of:

- mounting railing posts of a railing assembly on an upper ledger strip facing upward opposite the lower ledger strip and away from the lower floor and mounted on at least one said stairwell beam; and

- mounting a railing handrail of the railing assembly on the railing posts.

[0033] Conveniently, the step of mounting railing posts includes the step of mounting the railing posts on the upper ledger strip by adjustably positioning the railing posts lengthwise along an upper channel extending along the upper ledger strip.

[0034] Conveniently, the method further includes the step of mounting at least one transversal retaining bar of the railing assembly on at least two of the railing posts.

[0035] In one embodiment, the method further includes the step of mounting the at least one of the two stringers on the stringer anchors via transverse slots extending through the at least one of the two stringers and generally parallel to one another, each said transverse slot receiving a respective stringer anchor therein.

[0036] In one embodiment, the method further includes the step of slidably positioning the rear tread attachment of each said tread along a top portion of the at least one of the two stringers.

[0037] Conveniently, the method further includes the step of clamping a lower jaw body of the rear tread attachment, being slidably positionable along the top portion, onto the at least one of the two stringers at a predetermined position. [0038] Conveniently, the method further includes the step of supporting the rear side of the tread on an upper protrusion with a stem-mounted cylindrically rounded tip of the rear tread attachment movably mating with a corresponding slotted blind cavity extending into the rear side of the tread.

[0039] In one embodiment, the method further includes the step of securing top and bottom end parts of the front tread attachment connected to one another with an adjustable longitudinal attachment member to the front side of the tread and the rear side of the frontward adjacent one said tread, respectively.

[0040] In one embodiment, the method further includes the steps of:

- mounting an angle tread frame structure on frame anchors attached to selected ones of the plurality of posts; and

- mounting a plurality of angle treads on the angle tread frame structure.

[0041] Conveniently, the method further includes the step of securably connecting a front side of a lowermost said angle tread to the rear side of a frontward adjacent one said tread via a corresponding one said front tread attachment.

[0042] Conveniently, the method further includes the step of securably connecting a rear side of an uppermost said angle tread to the front side of a rearward adjacent one said tread via a corresponding one said front tread attachment.

[0043] In one embodiment, the method further includes the step of connecting a stair handrail to the at least two of the plurality of posts between the at least one of the two stringers and the upper floor.

[0044] Other objects and advantages of the present invention will become apparent from a careful reading of the detailed description provided herein, with appropriate reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Further aspects and advantages of the present invention will become better understood with reference to the description in association with the following Figures, in which similar references used in different Figures denote similar components, wherein:

Figure 1 is a top front perspective view of a construction staircase assembly in accordance with an embodiment of the present invention, extending between a lower floor and an upper floor;

Figure 2 is a top perspective view similar to Figure 1 , showing the cavity of the stairwell extending through the upper floor between the floor beams, and the positioning bars along the perimeter of the stairwell for receiving the stairwell beams there against;

Figure 3 is a bottom perspective view of a stairwell beam with the lower and upper ledger strips mounted thereon;

Figure 4 is an enlarged view of the of Figure 3;

Figure 5 is a top perspective view similar to Figure 2, showing the stairwell beams installed along the perimeter of the stairwell;

Figure 6 is a top perspective view of a railing post of the railing assembly;

Figure 7 is a bottom perspective view of the railing post of Figure 6, showing a railing post positioning bracket mounted there under;

Figure 8 is an enlarged top perspective view of the railing post positioning bracket of Figure 7;

Figure 9 is a top perspective view of a post of the staircase assembly, showing a post positioning bracket mounted thereon;

Figure 10 is an enlarged top plan view of the post of Figure 9;

Figure 11 is an enlarged top perspective view of the post positioning bracket of Figure 9;

Figure 12 is a side view of a stringer of Figure 1 , showing two slots extending there through for receiving a respective stringer anchor therein; Figure 13 is an enlarged end view of the post of Figure 12;

Figure 14 is an enlarged top perspective view of a stringer anchor of Figure 1 ;

Figure 15 is an enlarged top perspective view of a post supporting the stringer via a stringer anchor;

Figure 16 is an enlarged side view of a tread assembled to the stringer and connected to adjacent upper and lower treads via front and rear tread attachments, respectively;

Figure 17 is a top front perspective view of a tread of Figure 1 ;

Figure 18 is a rear front perspective view of a tread of Figure 1 ;

Figure 19 is an enlarged top perspective view of a rear tread attachment of Figure 16;

Figure 20 is an enlarged top perspective view of a front tread attachment of Figure 16;

Figure 21 is a top front perspective view of rear tread attachments of Figure 19 secured to the stringer after being slidably positioned thereon;

Figure 22 is a top front perspective view of the detail of the two lowermost treads of the staircase assembly to the stringer and the posts;

Figure 23 is a rear perspective view of the detail of the two treads of the staircase assembly to the stringer and the posts;

Figure 24 is a top front perspective view of the angle tread frame structure of Figure 1with the angle treads mounted thereon; and

Figure 25 is a side front perspective view of the angle tread frame structure of Figure 1 mounted on selected posts via frame anchors, and connected to upper and lower adjacent treads via rear tread attachments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] With reference to the annexed drawings the preferred embodiments of the present invention will be herein described for indicative purpose and by no means as of limitation. [0047] Referring first to Figure 1 , there is shown a construction site staircase assembly 30 in accordance with an embodiment of the present invention, extending between a lower floor 32 and an upper floor 34. The upper floor (as better seen in Figure 2) has an opening (or cavity) extending therethrough between the (engineered) floor beams 36 and defining a stairwell 38. The prefabricated assembly 30, generally needs to be installed at the early stage of the construction of the building to allow for the construction workers to go from one floor 32, 34 to the other 34, 32, while ensuring the required security (as per local construction /building code).

[0048] The assembly 30 typically includes a plurality of posts 40 extending between the upper 34 and lower 32 floors and that are connected to the floors 32, 34 and preferably directly secured to at least the lower floors 32. Stringer anchors 42 are attached (as detailed herein below) to at least two of posts 40, at predetermined locations. Stringers 44, positioned parallel and spaced from one another, are mounted on and secured to the anchors 42, such that they are supported by the posts 40. Although not illustrated herein, the stringer anchors 42 could also be direct attachment or securing members which would support the stringers 44 mounted thereon.

[0049] A plurality of treads 46, equally spaced from one another and positioned along two of the stringers 44, and each tread 46 defines a rear side 48 thereof attaching to the two stringers 44 via a respective rear tread attachment 50 and a front side 52 thereof securably connecting to the rear side 48 of a frontward adjacent tread 46 via a front tread attachment 54.

[0050] Although further detailed herein below, the rear tread attachment 50 of each tread 46 is slidably adjustably positioned along the two stringers 44 and allows for angular pivoting adjustment of the tread 46 relative to the two stringers 44 about a pivoting axis 56 generally perpendicular to the two stringers 44. Similarly, the front tread attachment 54 of each tread 46 (but typically not for the frontward most (or lowest or first) tread) is adjustable in length to allow adjustment of a height between the two adjacent treads 46 connected thereto to ensure a horizontal levelling of the tread 46. It is noted that the slidable adjustment positioning of the different rear tread attachments 50 along the stringer 44, as well as the length adjustment of the different front tread attachments 54 are all properly performed in factory (prior to shipment of the assembly 30 to the construction site).

[0051] Now referring more specifically to Figures 2-5, the assembly 30 typically includes a stairwell frame 60 (or module) adapted to be installed on the upper floor 34 at a perimeter 39 of the stairwell 38. The stairwell frame 60 typically includes a plurality of (engineered) stairwell beams 62 (as better seen in Figures 3 and 4) positioned in an end-to-end configuration along (or around) the perimeter 39. In order to easily position the different stairwell beams 62 on the floor 34, supporting slats 64 (as better seen in Figure 2) are mounted all along the perimeter 39. Each stairwell beam 62 typically includes a positioning slat 66 adapted to sit on a corresponding supporting slat 64. Where needed, the stairwell beam 62 includes a lower ledger strip 68, facing downward toward the lower floor 32, mounted there under to connect to at least one post 40. The lower ledger strip 68 includes a preferably T-shape lower channel 70 extending there along to allow for a lengthwise adjustable positioning of the selected posts 40 along the lower ledger strip 68. It is noted that the upper ledger strip 72 includes a lower flange 75 extending longitudinally all along the strip 72 to help positioning of the strip 72 on the stairwell beam 62 and allow to hide a cut edge of a piece of gypsum board (not shown) or the like covering the side of the stairwell beam 62. Also, the longitudinal ends of the upper 72 and lower 68 ledger strips are typically angled or beveled to allow for miter joints therebetween upon assembly of the stairwell frame 60.

[0052] Now referring more specifically to Figures 6-8, the assembly 30 typically includes a railing assembly 80 (or module) having safety railing posts 82 to securably support a railing handrail 84 mounted thereon, as well as at least one transversal retaining bar 86 mounting on at least two of the railing posts 82 slid inside corresponding bar loops 88, and secured to the railing posts 82 using securing screws or the like through corresponding securing holes 90. It is noted that transversal retaining bars 86’ essentially restraining access to the staircase from the upper floor 34 are simply removably attached to the adjacent transversal retaining bars 86 of the railing assembly 80. [0053] Each railing post 82 typically mounts on an upper ledger strip 72 mounted on the stairwell beam 62 and facing upward opposite the lower ledger strip 68 and away from the lower floor 32. The upper ledger strip 72, similarly to the lower ledger strip 68, includes a preferably T-shape upper channel 74 extending there along to allow for a lengthwise adjustable positioning of the selected railing posts 82 along the upper ledger strip 72. Each railing post 82 is mounted on the corresponding upper ledger strip 72 via a guiding insert bracket 92 attached at the bottom end of the railing post 82 (as better seen in Figures 7 and 8) that is first inserted into the upper channel 74 then slid at the required position there along then rotated by about ninety degrees (90°) about the post axis to hold it in place (via two opposite rounded corners 93 of the rectangular shape of the guiding insert bracket 92), then secured to the upper ledger strip 72 via the post lower plate 94 using securing screws or the like.

[0054] It is noted that, upon dismantlement of the railing assembly 80, the railing posts 82 are removed from the upper ledger strips 72, and the upper ledger strips 72 are then used as guides to support, via the stairwell beams 62 of the stairwell frame 60, the wall structure of the future walls of the building that will form the building stairwell.

[0055] Now referring more specifically to Figures 9-11 , each post 40, similarly to the railing post 82, is mounted under the corresponding lower ledger strip 68 via a guiding insert bracket 96 attached at the top end of the post 40 (as better seen in Figures 9 and 11) that is first inserted into the lower channel 70 then slid at the required position there along then rotated by about ninety degrees (90°) about the post axis to hold it in place (via two opposite rounded corners 97 of the rectangular shape of the guiding insert bracket 96), then secured to the lower ledger strip 68 via the post bracket plate 98 using securing screws 99 or the like. As illustrated in Figure 10, each post 40 typically has the shape of an I-beam with the height of the l-shape corresponding to the typical width od a standard construction wall stud, as the post could eventually be part of a future wall. To this end, two adjacent post 40 would typically be spaced apart from each other by a multiple of the conventional wall stud spacing, such as typically a multiple of 16 inches (40 cm) in North America. Also, although not illustrated, the bottom end of the posts 40 are typically secured to the lower floor 32 by any suitable attachment well known in the art.

[0056] Now referring more specifically to Figures 12-15, at least one (all in the present embodiment 30) of the stringers 44 includes a plurality of transverse slots 100 extending there through and generally parallel to one another. Each slot receiving a respective stringer anchor 42 therein, and the stringer anchors 42 secure the stringer 44 in place. More specifically, an end plate 102 of the stringer anchor 42 is secured to the post 40. A blind hole 104 (see bottom of Figure 9) is typically machined into the post 40 to receive therein a screw head (not shown) of the screw securing the end plate 102 to the cylindrical body 106 of the anchor 42. At the opposite longitudinal end of the anchor 42, the stringer 44 is clamped between two washers 108 with a cylindrical spacer 110 therebetween. The spacer 110 is adapted to slide into the corresponding slot 100 of the stringer 44 and support the stringer 44 thereon. As shown in Figures 13 and 15, the stringer 44 typically has a l-shape cross-section and the two washers 108 clamps onto the central web 112 of the l-shape.

[0057] Now referring more specifically to Figures 16-23, the front tread attachment 54 (best seen in Figures 16, 20 and 22-23) includes top and bottom end parts 114 connected to one another with an adjustable longitudinal attachment member 116. The top and bottom end parts 114 are typically secured to the front side 52 of the tread 46 and the rear side 48 of the frontward adjacent tread 46, respectively. The adjustable longitudinal attachment member 116 typically includes a threaded rod connecting to corresponding threaded holes extending into the top and bottom end parts 114 and a locking nut 116’. If desired, as best seen in Figure 22, the frontward most or lowest or first tread 46’ could have a front tread attachment 54’ in the form of a riser plate attached to the front side 52 of the tread 46’ and connectable (simply in abutment, spaced or secured, for example) to the lower floor 32. Each straight section of the staircase assembly (using a pair of stringers 44) can be considered as a suitcase module of the staircase assembly 30.

[0058] Also, the rear tread attachment 50 (best seen in Figures 19, 21 and 22-23) includes a lower jaw body 118 slidable along the preferably T-shaped top portion 119 or flange of the stinger 44 and clamped there onto, via clamping screws 120, at a respective predetermined position. The preferred trapezoidal shape of the top portion of the l-shape of the cross-section of the stringer 44 allows for a easy proper clamping of the rear tread attachment 50 thereon. Furthermore, the rear tread attachment 50 typically includes an upper protrusion 122 with a stem-mounted cylindrically rounded tip 124 movably mating with and supporting thereon a corresponding slotted blind cavity 126 extending into the rear side 48 of the tread 46 (best seen in Figures 17 and 18). The slotted blind cavity 126 enables for insertion of the cylindrically rounded tip 124 therein and an easy angular pivoting adjustment of the tread 46 relative to the two (one at each longitudinal end of the tread 46) stringers 44 about the pivoting axis 56 to allow for subsequent securing of the front tread attachment 54 to the frontward adjacent tread 46.

[0059] These height adjustments of the front tread attachments 54, as well as the slidable positioning adjustments and securing of the rear tread attachments along the corresponding stringer 44 are typically all performed in factory prior shipping and installation of the assembly 30 on site.

[0060] As a person skilled in the art would appreciate, the treads 46 of the assembly 30 are preferably assembled starting with the lowest or first tread 46’ followed successively by the adjacent treads 46 going upward, from the lower floor 32 to the upper floor 34.

[0061] Now referring more specifically to Figures 24 and 25, the illustrated assembly of the present embodiment 30 includes an angle tread frame structure 130 mounting on frame anchors 132, similar to the stringer anchors 42, attached to selected posts 40, and a plurality of (three (3) in the present case) angle treads 134 mounting on the angle tread frame structure 132 (although a right angle (90°) frame structure 130 /module is illustrated herein, between upper and lower straight portions /modules of the staircase assembly 30, a person skilled in the art would readily understand that any angle and/or any location of the frame structure 130 could be considered without departing from the scope of the present invention). The lowermost or first angle tread 134 typically has a front side 52 thereof securably connecting to the rear side 48 of the frontward adjacent tread 46 via a corresponding front tread attachment 54”, and the uppermost or last angle tread 134 has a rear side 48 thereof securably connecting to the front side 52 of the rearward adjacent tread 46 via a corresponding front tread attachment 54.

[0062] Also, as seen in Figure 1 , the assembly includes at least one stair handrail 128 connecting to at least two posts 40 at a proper height (usually dictated by local building codes) above the treads 46, between the stringers 44 and the upper floor 34.

[0063] The present invention also refers to a method for assembling a staircase assembly 30 on a construction site of a building between upper 34 and lower 32 floors, with the upper floor 34 having an opening extending therethrough and defining a stairwell 38, the method comprising the steps of:

- connecting a plurality of posts 40 extending between the upper 34 and lower 32 floors to the upper 34 and lower 32 floors;

- attaching stringer anchors 42 to at least two of the plurality of posts 40;

- positioning two stringers 44 parallel to and spaced from each other, and mounting at least one of the two stringers 44 on the stringer anchors 42; and

- positioning a plurality of treads 46 equally spaced from one another along the two stringers 44 by attaching a rear side 48 of each said tread 40 to the two stringers 44 via a respective rear tread attachment 50 being slidably adjustably positioned along the two stringers 44 and allowing angular pivoting adjustment of the tread 46 relative to the two stringers 44 about a pivoting axis 56 generally perpendicular to the two stringers 44, and by securably connecting a front side 52 of at least each said tread 46 but a frontward most said tread 46’ to the rear side 48 of a frontward adjacent one said tread 46 via a front tread attachment 54 being adjustable in length to allow adjustment of a height between the two adjacent said treads 46 connected thereto thereby ensuring a horizontal levelling of the tread 46. [0064] Typically, the step of connecting a plurality of posts 40 includes the steps of:

- installing a stairwell frame 60 on the upper floor 34 at a perimeter 39 of the stairwell 38 by positioning a plurality of stairwell beams 62 of the stairwell frame 60 in an end-to-end configuration along, or around, the perimeter 39; and

- connecting at least one said post 40 to a lower ledger strip 68 facing downward toward the lower floor 32 and mounted under at least one said stairwell beam 62.

[0065] Typically, the step of connecting at least one said post 40 includes the step of connecting the at least one said post 40 to the lower ledger strip 68 by adjustably positioning the at least one said post 40 lengthwise along a lower channel 70 extending along the lower ledger strip 68.

[0066] Typically, the method further includes the steps of:

- mounting railing posts 82 of a railing assembly 80 on an upper ledger strip 72 facing upward opposite the lower ledger strip 68 and away from the lower floor 32 and mounted on at least one said stairwell beam 62; and

- mounting a railing handrail 84 of the railing assembly 80 on the railing posts 82.

[0067] Typically, the step of mounting railing posts 82 includes the step of mounting the railing posts 82 on the upper ledger strip 72 by adjustably positioning the railing posts 82 lengthwise along an upper channel 74 extending along the upper ledger strip 72.

[0068] Typically, the method further includes the step of mounting at least one transversal retaining bar 86 of the railing assembly 80 on at least two of the railing posts 82.

[0069] Typically, the method further includes the step of mounting the at least one of the two stringers 44 on the stringer anchors 42 via transverse slots 100 extending through the at least one of the two stringers 44 and generally parallel to one another, each said transverse slot 100 receiving a respective stringer anchor 42 therein.

[0070] Typically, the method further includes the step of slidably positioning the rear tread attachment 50 of each said tread 46 along a top portion 119 of the at least one of the two stringers 44.

[0071] Typically, the method further includes the step of clamping a lower jaw body 118 of the rear tread attachment 50, being slidably positionable along the top portion 119, onto the at least one of the two stringers 44 at a predetermined position.

[0072] Typically, the method further includes the step of supporting the rear side 48 of the tread 46 on an upper protrusion 122 with a stem-mounted cylindrically rounded tip 124 of the rear tread attachment 50 movably mating with a corresponding slotted blind cavity 126 extending into the rear side 48 of the tread 46.

[0073] Typically, the method further includes the step of securing top and bottom end parts 114 of the front tread attachment 54 connected to one another with an adjustable longitudinal attachment member 116 to the front side 52 of the tread 46 and the rear side 48 of the frontward adjacent one said tread 46, respectively.

[0074] Typically, the method further includes the steps of:

- mounting an angle tread frame structure 130 on frame anchors 132 attached to selected ones of the plurality of posts 40; and

- mounting a plurality of angle treads 134 on the angle tread frame structure 130.

[0075] Typically, the method further includes the step of securably connecting a front side 52 of a lowermost said angle tread 134 to the rear side 48 of a frontward adjacent one said tread 46 via a corresponding one said front tread attachment 54. [0076] Typically, the method further includes the step of securably connecting a rear side 48 of an uppermost said angle tread 134 to the front side 52 of a rearward adjacent one said tread 46 via a corresponding one said front tread attachment 54.

[0077] Typically, the method further includes the step of connecting a stair handrail 128 to the at least two of the plurality of posts 40 between the at least one of the two stringers 44 and the upper floor 34.

[0078] The various features described herein can be combined in a variety of ways within the context of the present disclosure so as to provide still other embodiments. As such, the embodiments are not mutually exclusive. Elements of the embodiments and examples discussed can be combined within the context of the disclosure as those having skill in the art will readily appreciate. Moreover, the embodiments discussed herein need not include all of the features and elements illustrated and/or described and thus partial combinations of features can also be contemplated. Furthermore, embodiments with less features than those described can also be contemplated. It is to be understood that the present disclosure is not limited in its application to the details of construction and parts illustrated in the accompanying drawings and described hereinabove. The disclosure is capable of other embodiments and of being practiced in various ways. It is also to be understood that the phraseology or terminology used herein is for the purpose of description and not limitation. Hence, although the present disclosure has been provided hereinabove by way of non-restrictive illustrative embodiments thereof, it can be modified, without departing from the scope and nature thereof and of the appended claims.