CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and/or priority to U.S. Patent Application No. 15/844,029, filed on December 15, 2017, entitled MODULAR STAIR SYSTEM (Atty. Dkt. No. PTMG60-33801), which is incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] This application relates to a system and method for building stairs, and more particularly, to a system and method for building a modular stair system.

BACKGROUND

[0003] In both residential and commercial construction, the building of stairs enabling access from one level to another is a time-consuming process. Normally, the levels of a building structure are constructed and at some later point in time the stairs between levels are built as part of the previously built structure. In normal circumstances, this may take several days in order to build the stairs from the ground floor to the upper floors in a multilevel structure. Additionally, when stairs from one level to another level have not been completed, alternative methods for moving between the levels, such as ladders, must be used to enable workers and inspectors to move between the different levels. The use of ladders and other temporary means for moving between levels are less safe than a normal stair structure. Thus, there is a need for the ability to more quickly construct stair structures within a residential or commercial construction that improves safety at the construction work site and minimizes construction time to improved efficiencies.

SUMMARY

[0004] The present invention, as disclosed and described herein, in one aspect thereof, comprises a modular stair system comprises a plurality of modular stair units. Each of the plurality of modular stair units are associated with a single story of a construction. An upper, rectangular landing comprises a pair of long members connected at each end to a pair of short members. A first plurality of comer brackets connect an end of a long member to an end of a short member. The plurality of comer brackets have a variable size depending on a number of the plurality of modular stair units to be stacked in a stairwell. A mid-level, rectangular landing comprises a first pair of members and a second pair of members interconnected at their ends. A second plurality of comer brackets interconnects an end of the first member with an end of the second member. The second plurality of comer brackets have the variable size depending on the number of the plurality of modular stair units to be stacked in the stairwell. A plurality of comer support columns support the upper, rectangular landing at a top portion thereof and the mid-level, rectangular landing at a mid-portion thereof. The plurality of comer support columns are removably connected to the upper, rectangular landing and the mid-level, rectangular landing. The plurality of comer support columns have a second variable size depending on the number of the plurality of modular stair units to be stacked in the stairwell. A first stair runner removably connects to the mid-level landing and connects a bottom level to the mid-level landing. A second stair runner removably connects to the mid-level, rectangular landing and the upper, rectangular landing to connect the mid level, rectangular landing to the upper, rectangular landing. Each of the plurality of modular stair units are organized such that a bottom modular stair unit is placed on a foundation and each successive modular stair unit of the plurality of modular stair units are stacked on top of and connected to a lower modular stair unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which:

[0006] Fig. 1 illustrates a perspective view of the modular stair unit;

[0007] Fig. 2 illustrates a side view of the modular stair unit;

[0008] Fig. 3 illustrates an end view of the modular stair unit;

[0009] Fig. 4 illustrates an assembled stairwell structure using modular stair units;

[0010] Fig. 5 illustrates a flow diagram describing the process for building a modular stair unit;

[0011] Fig. 6 illustrates a flow diagram describing the process for assembling a stairwell;

[0012] Fig. 7 illustrates a configurable comer bracket;

[0013] Fig. 8 illustrates a comer support column;

[0014] Fig. 9 illustrates a foundation connection plate;

[0015] Fig. 10 illustrates a first side view of a connection sleeve and comer column;

[0016] Fig. 11 illustrates a second side view of a connection sleeve and comer column;

[0017] Fig. 12 illustrates a connection sleeve interconnecting first and second comer columns;

[0018] Fig. 13 illustrates a cross-sectional view of a stair runner;

[0019] Fig. 14 illustrates connection brackets for a stair runner; [0020] Fig. 15 illustrates a top view of an upper level landing; [0021] Fig. 16 illustrates the connection of the modular stair unit to a structure using Nelson studs; and

[0022] Fig. 17 illustrates a flow diagram describing the process for removing support columns from the self-supporting modular stair unit.

DETAILED DESCRIPTION

[0023] Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of a modular stair system are illustrated and described, and other possible embodiments are described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments.

[0024] A modular stair unit 102 is illustrated in Figs. 1-3. Fig. 1 illustrates a perspective view of the modular stair unit 102. Fig. 2 illustrates a side view of the modular stair unit, and Fig. 3 illustrates an end view of the modular stair unit. The modular stair unit 102 includes a top landing 104 and mid-landing 106. The top landing 104 is raised into the air using a group of four comer columns 108 and two central columns 110. The comer columns 108 are removably connected to each comer of the top landing 104 using bolts or some other type of removable connecting means. The comer columns 108 in one embodiment comprise square tubular steel components of variable size. The size of the comer columns 108 may be adjusted based upon the number of stair modules 102 that are to be stacked upon one another. Larger rectangular sized columns 108 would be utilized for stacking more modules 102 on top of one another. The center columns 110 are mounted at some location along the long edge of the top landing 104 and are removably connected to the top landing 104 using bolts or some other type of removable connection.

[0025] The top landing 104 consist of a number of members connected in a rectangular shape having a pair of long sides 112 and a pair of short sides 114. Long members 112 and short members 114 are bolted together at their ends as will be more fully described herein below, to provide for the connection of different sizes of comer columns 108. In one embodiment, the long members 112 and the short members 114 comprise 12 inch beams.

[0026] The mid-landing 106 is adjustably connected to a point on a pair of the comer columns 108 and a pair of the center columns 110. Using bolts or some other type of removable connecting mechanism the mid-landing 106 may be moved to a plurality of locations between the top end of the pair of comer columns 108 and the pair of center columns 110 and the bottom of these columns. The mid-landing 106 also comprises a pair of long members 116 and a pair of short members 118 that are interconnected at their ends to form a rectangle that bolts to the comer columns 108 and center columns 110 as will be more fully described herein below. The long members 116 and short members 118 comprise in one embodiment 12 inch beams.

[0027] A lower stair runner 120 provides steps from the ground level or floor level to the mid-landing 106. The upper stair runner 122 provides steps from the mid-landing 106 to the top landing 104. The lower stair runner 120 is removably connected to the mid-landing 106 using bolts or some other type of removably connectable mechanism. The upper stair runner 122 is removably connected to the mid-landing 106 and the top landing 104 using bolts or some other type of removably connectable mechanism. Each of the lower stair runner 120 and the upper stair runner 122 consist of a pair of stringers 202 located on each side of the runners with a plurality of tread pans 124 located there between. The tread pans 124 consist of a metal well that can be filled with concrete in order to provide a step tread. The tread pans 124 may be used as stairs before the concrete is poured therein further speeding use of the stair modules 102 when assembled.

[0028] A number of railings 126 surround the outer edges of the upper landing 114 mid landing 116 and each of the upper stair runner 122 and lower stair runner 120. The railings are removably connected via bolts or some other type of removable connection mechanism and provide for safety of individuals using the modular stair system 102.

[0029] Referring now to Fig. 4, there is illustrated an assembled stairwell structure 402 utilizing four different modular stair units 102. The bottom modular stair unit 102A is secured to the foundation using a number of foundation brackets 404. The foundation brackets 404 are secured to the foundation using some type of foundation bolts, foundation screws or other type of foundation securing mechanism. Once the bottom modular stair unit 102 A has been secured to the foundation, a next modular stair unit 102B is lowered into place on top of the bottom modular stair unit 102A. The modular stair unit 102B and the modular stair unit 102 A are interconnected at their comer columns 108. The bottom of the comer columns 108 of the upper modular stair unit 102B are connected to the top of the comer columns of the bottom modular stair unit 102A using a connection sleeve 1002 (Fig. 10), as will be more fully described hereinbelow. The connection sleeve 1002 slides within the rectangular tubular member comprising the comer columns 108 and are then bolted thereto allowing the modular stair units 102A and 102B to be securely fastened to each other at each of the comer columns.

[0030] Modular stair unit 102C connects to modular stair unit 102B in a similar fashion. The base of the comer columns 108 of modular stair unit 102C are connected to the top of the comer columns 108 of modular stair unit 102B using the connection sleeve 1002. Likewise the top modular stair unit 102D has the base of its comer columns 108 connect to the top of the comer columns 108 of modular stair unit 102C. Each of the modular stair units 102 are lowered into place on the foundation or on to the previously placed modular stair unit using a crane. Referring now to Fig. 5, there is illustrated a flow diagram describing the process for assembling stairwell using the above described modular stair units 102. Initially, the individual modular stair units 102 are constructed at a remote location. The number of modular stair units 102 necessary for a particular construction site are constmcted based upon the number of stairwells needed at a construction site and the number of levels within the structure being built. Once the required number of modular stair units 120 have been constructed, the modular stair units are disassembled at step 504 into their component parts. As discussed previously, the component parts comprise the top landing 104, mid-landing 106, upper stair runner 120, lower stair runner 122, comer columns 108, center columns 110 and railings 126. Each of these individual components are separated from each other by disconnecting the associated nut and bolt connections or other type of removable connection assembly utilized.

[0031] Next, each of the individual component parts are loaded onto trailers and transported at step 506 to the construction site. Once the disassembled modular stair units 102 arrive at the construction site, the modular stair units are reassembled at step 508 utilizing the same previously discussed nut and bolt type or other connection assembly utilized in the construction. Once the modular stair units 102 have been reassembled, the modular stair units may be stacked to construct a stairwell in a manner that will now be more fully discussed with respect to Fig. 6. Within the stacking process, the bottom modular stair unit 102 is first anchored at step 602 to the foundation of the structure. Next, the second modular stair unit 102 for the second floor is lowered on to the previously placed modular stair unit. The bottom of the comer columns 108 of the second modular stair unit 102 are aligned with the top of the comer columns of the lower modular stair unit and the second modular stair unit is leveled at step 606. The leveling mechanism will be more fully described hereinbelow. Once the second modular stair unit 102 is leveled, the second modular stair unit is connected at step 608 to the lower modular stair unit using the connection sleeves 1002. This process may then be repeated for each additional level by stacking the upper modular stair unit 102 onto the lower modular stair unit and connecting the comer columns 108 in a similar fashion. Once each of the modular stair units 102 have been placed and connected, the concrete stair treads may be poured at step 610 for each of the treads within the stairwell and the associated tread pans.

[0032] In this manner, a multi-level stairwell can be quickly built in just a few hours. Normally, the construction of a set of stairs within a multi-level structure will take several days in order to completely build the stair structure. By using the described modular stair units, the process may be completed in hours rather than days. The process additionally provides a number of safety factors to the construction site. Normally, a floor level must be created before the associated stair structure can be built as the stair structure is connected to and supported by the surrounding floor level. The modular stair unit system is self- supporting and can be erected even before any of the surrounding construction has been started. The associated floor level may then be built around the already established stairwell. The ability to erect the stair structure prior to or substantially concurrent with the building of the associated floor levels provides a high safety factor in that workers and inspectors are provided with a quicker ability to move between floors rather than using temporary ladders or other hazardous configurations.

[0033] A number of particular components enable the modular stair units 102 to be assembled as discussed in Fig. 5 and combined with other modular stair units as discussed in Fig. 6 in order to provide a multilevel stair structure. Referring now to Fig. 7, there is illustrated the adjustable manner in which the long sides 112 and short sides 114 of the top landing 104 may be connected with each other at their ends in order to provide a configurable connection for the use of different sized comer columns 108. The long sides 112 and short sides 114 of the top landing 104 are interconnected via an L-shaped comer bracket 702. The comer bracket 702 comprises a first member 704 and a second member that are interconnected along an edge 708 at an orthogonal angle. The comer bracket 702 also defines holes 710 within the members 704 and 706 to enable the comer bracket to be bolted to a comer column 108. The holes 710 aligned with corresponding holes on the comer columns 108 in order to enable the comer columns and comer brackets to be bolted to each other. The comer bracket 702 is connected to the long member 112 and short member 114 via welding, bolting or other connection means. Since the long members 112 and short members 114 of the top landing 104 are interconnected with the comer bracket 202, the comer bracket 202 may be configured in different embodiments to bolt the two landings to different sized comer columns 108. Thus, the comer bracket 702 may have different sizes in order to accommodate different sized comer columns 108. A top landing 104 may be configured for different sized comer columns 108 by merely utilizing the appropriate comer bracket 702. Differing size comer columns 108 and comer brackets 702 would be utilized depending upon the number of modular stair units 102 that were to be stacked for a particular stairwell. A greater number of stacked modular stair units 102 require the use of larger comer columns 108 as the structure is self-supporting and larger beams are needed to support the greater weight of more modular stair units within a stack.

[0034] Referring now also to Fig. 8, there is illustrated a comer column 108. As mentioned above, the comer columns can be different sizes depending on the number of levels to be supported in the stair well. The comer column 108 includes holes 802 located at a top end thereof. The holes 802 located at the top end of the comer column 108 enable the modular stair unit 102 stacked on top of the comer columns 108 to be leveled through a connection sleeve as will be more fully described herein below. Multiple holes 802 allow comers of the modular stair unit 102 above the column 108 to be placed at various levels. The comer columns 108 are constructed of a rectangular tubular steel and may be of different sizes depending upon the number of levels to be stacked in a particular stairwell. Thus, larger comer columns 108 may be utilized when a greater number of modular stair units 102 are to be stacked on top of one another.

[0035] Referring now to Fig. 9, there is illustrated a foundation support plate 902. The foundation support plate 902 would be welded or connected in some other means to a bottom end of a comer column 108 of the lowest level modular stair unit 102 of a stairwell in area 906 indicated generally in Fig. 9. The foundation support plate 902 would be connected to the bottom end of each of the comer columns 108 and enable the base of the stairwell structure to be secured to a foundation. The foundation support plate 902 defines multiple holes 904 therein which may be used for securing the modular stair unit 102 to the foundation using bolts, screws or some other type of foundation connecting means. [0036] Referring now to Figs. 10 and 11, there is illustrated one side of the connection sleeve 1002. The connection sleeve 1002 is a rectangular tubular member having a size enabling the connection sleeve to be slid within the interior of the comer columns 108. On a first pair of sides 1004, the connection sleeve 102 defines a lifting eye 1006. The lifting eye 1006 enables a hook, strap, cable, etc. to be inserted therein and used for lifting a modular stair unit 102 into which the connection sleeve 902 has been installed within a comer column 108. The associated modular stair unit 102 may be lifted into the air using the lifting eye 1006 to enable the modular stair unit to be placed upon another modular stair unit within a stairwell. Located on a second pair of sides 1108 of the connection sleeve 1002 are a plurality of leveling holes 1010. The leveling holes 1010 of the connection sleeve 1002 may be aligned with corresponding leveling holes 1012 located on the comer column 108. The connection sleeve 1002 slides into the interior of the comer column 108 and the leveling holes 1010 are aligned with a desired leveling hole 1012 within the comer column. A bolt may then be placed through the aligned leveling holes 1010 and 1012 to maintain the connection sleeve 1010 at a desired level.

[0037] Referring now to Fig. 12, there is illustrated a connected pair of comer columns 108 using a connection sleeve 1010. As discussed previously, the connection sleeve 1010 slides within the comer columns 108. The connection sleeve 1010 is maintained at a selected height by placing a bolt 1202 through an aligned pair of leveling holes 1010/1012 within the connecting sleeve 1002 and comer column 108. Once the connection sleeve 1002 is secured within the lower comer column 108A, the upper comer column 108B may be lowered onto the connection sleeve 1010 and once it has been set to a desired height, a bolt 1202 may be used for securing the upper comer column 108 to the connection sleeve 1010 through aligned leveling holes 1010/1012.

[0038] Referring now to Fig. 13, there is illustrated a cross-sectional side view of a stair runner 1302 that interconnects a lower level to the mid-level landing 106 or the mid-level landing to the top landing 104. This may be the upper or lower stair runner as described earlier. The stair runner 1302 consists of a stringer 1304 located on each side of the stair runner to support a number of tread pans 1306. The tread pans 1306 connect to and are supported by the stringers 1304 located on each side thereof and further connect to the tread pans above and below the tread pan along the top and bottom edges. In the case of the top tread pan 1306A, this tread pan connects to the top edge 1308 of the stair runner 1302 and the tread pan immediately following the top tread pan. The tread pan 1306 includes a concrete holding well 1310 into which concrete may be poured after the stairway has been installed to provide a tread walking area for the stairway. However, it should be realized that the tread pan 1306 may be used prior to the pouring of concrete into the holding well 1310 by construction workers and inspectors. Also mounted to each side of the stringers 1304 are railings 1312 that may be of various configurations depending upon local building codes and/or construction requirements. The railings 1312 are bolted at the bottom of vertical support posts 1314 to the stair stringers 1304.

[0039] Referring now also to Fig. 14, there is illustrated a back side view of the stair runner 1302. In order to connect stair runner 1302 to either the mid-level landing 106 or top landing 104, a pair of mounting plates 1402 are connected to each of the stringers 1304 of the stair runner 1302. The mounting plates 1404 include a pair of holes 1404 therein for bolting the top edge of the stair runner 1302 to a crossbeam of the mid-level landing 106 or top landing 104. The use of bolts and the mounting plates 1402 enable the stair runner 1302 to be quickly and easily removed from or attached to the modular stair assembly 102 to enable transport to a construction site.

[0040] Referring now to Fig. 15, there is illustrated a top view of the top level landing 104. The top level landing 104 consists of it the long side members 112 interconnected with the short side members 114 using comer brackets 702. The size of the landing platform upon the top level landing 104 is adjustably configurable by movement of the support beams. Thus, as illustrated in Fig. 15, support beams 1502, 1504 and 1506 are movable in two directions as indicated generally by arrows 1508. In this manner, the platform area can be adjusted to provide more or less area as desired and may also provide for differing size stair runners running from the mid-level landing 106 to the top level landing 104. Alternatively, the platform size may be adjusted to compensate for door opening placement within the associated construction. In this manner, the top level landing 104 may be configured to fit within a number of different configurations of stair runner length and construction door openings to facilitate construction differences. The associated crossbeams 1510 within the landing may be sized to fit within the construction. While the above discussion has been made with respect to the top level landing 104, the mid-level landing 106 may be configured in a similar manner to enable for differences in size of the platform landing, differing door opening placements and differing sizes of stair runners utilized within the construction of a modular stair unit 102.

[0041] One advantage of the modular stair unit 102 configuration is that the units in both the individual and stacked configurations are self-supporting with the comer columns 108 and center columns 110 supporting the stairwell structure without any additional support from surrounding construction. In an alternative configuration, it is also possible for the modular stair units 102 to be supported by the surrounding construction rather than be self- supporting. In the alternative configuration, the modular stair units are placed and stacked upon one another as have been previously described hereinabove. However, as illustrated in Fig. 16, the modular stair units 102 may also include a plurality of Nelson studs 1602 that are welded to or connected in some other manner to the beams forming the sides of each of the top level landing 104 and mid-level landing 106. Each of the long and short beams within the top level landing 104 and mid-level landing 106 include a plurality of Nelson studs 1602 along their length. These Nelson studs 1602 would be extended into a form area 1604 that comprises a concrete form that is a part of the building structure for containing poured concrete around the Nelson studs 1604. After the Nelson studs 1602 are appropriately located within the form area 1604, the form area 1604 is filled with concrete 1606. The previously built sides 1608 of the form area 1604 and the beam of the top level layer 104 or mid-level layer 106 contain the concrete 1606 within the form area and upon hardening of the concrete enables the surrounding structure to support the top landings 104 and mid-level landings 106 without requiring the support of the comer columns 108 and center columns 110. This enables the comer columns 108 and center columns 110 to be unbolted from the top landing 104 and mid-level landing 106 and read moved from the stairwell structure. The stairwell structure remains in place due to the support of the surrounding structures provided through the Nelson studs 1602.

[0042] Referring now to Fig. 17, there is illustrated a flow diagram more particularly describing the process for building a stairwell structure that is supported by the surrounding constmction rather than being completely self-supporting using support columns of the modular stair unit 102. The process is initiated in a similar manner to that described herein above wherein the modular stair system is constructed by stacking and connecting the modular stair units 102 on top of each other until the desired number of levels is achieved at step 1702. During the stacking process, each of the modular stair units 102 are positioned such that Nelson studs 1602 attached to the modular stair units 102 are appropriately located within the associated form area 1604 at step 1704. Concrete is poured at step 1706 into the associated form areas 1604 and the concrete is allowed at step 1708 to harden. Once the concrete has hardened and the surrounding structure can support the top level landing 104 and mid-level landing 106, the support columns are removed at step 1710 to allow the modular stair units 102 to be completely supported by the surrounding structure.

[0043] In this manner, the speed of stair construction at a commercial or residential site can be greatly increased over current construction methods. As mentioned previously, existing construction methods can take several days to completely construct stairwells within a structure that is being built. Utilizing the above described modular stair units 102, a stairwell can be constructed in several hours rather than several days. This provides a great cost savings due to the greatly decreased amount of time required in the construction process. The described system also increases work place safety since stair structures for accessing different floors in a multilevel structure are provided much earlier in the construction process and no longer the require the use of temporary measures such as ladders in order to move between building levels.

[0044] It will be appreciated by those skilled in the art having the benefit of this disclosure that this modular stair system provides a manner for more efficiently constructing stairs within a residential or commercial construction. It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, it’s included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.