Staircase jig

Abstract: The staircase jig comprises a rack (12) provided with a resting surface (14) that lies on the front edge (15) of the lip of the first step,an element (18) with a vertical projection (19) for engaging the adjacent upper riser (4) and a rest (22) for engaging the underside of the lip of the next upper step together with a regulable stop (23) for the front of the lip of the next upper step. Two such racks (12) can be provided, joined by a telescoping longitudinal bar (13). The purpose of the jig is to ensure that each tread and riser combination has the same depth of tread, height of riser and lip projection.

Description: OBJECT OF THE INVENTION This invention concerns a staircase module positioner tool whose obvious purpose is to regulate the depth of each step, the verticality of the step riser or rear wall, and the difference in level between steps, all drawn from the horizontal plane of the first step. Thereore with the aforesaid horizontal plane of the first step, the positioner tool herein invented may be used to obtain step depth, the verticality of the step's riser or rear wall, and the difference in level between said first step plane and the next step plane which will lie parallel to the first, serving as a reference for all following step planes. The tool also works to fix the distance between the edge of the first step and the edges of following steps in vertical projection so that an exact number of modules will fit in between the bottom of the first step and the edge of the plane to which the staircase leads. In short, the aim is to maintain a constant step height and depth in a staircase of a given height and projection, while the depth and height of each step will be the result of dividing the height and projection exactly by the same number. STATE OF THE ART Staircase designing begins by calculating to find the number of steps, their height and their depth. First a master ramp is laid out. This ramp may be arched, and it serves as a foundation so that the bore of the staircase itself can be roughed out and later covered with slabs or prefabricated components and thus finished. It is necessary for an overhang to lie between each step riser and the plane of the next step, and this overhang must always jut out to exactly the right extent. It is also necessary for the proportions between the plane of any given step and the rest of the steps to be exact, since otherwise the staircase will trip up its users in the classic stair "traps", causing them to stumble and/or fall. Document DE-A-8609211 discloses an staircase positioner tool with different embodiments according to the way it is aplied to different kind of steps or to the same kind of step. In all these cases, it is only posible with this tool to regulate the verticality of the riser and the depth of the step, but it doesn't incorporate fixing means that provides the accuracy required when it is used on the steps, and it has not the posibility to regulate the right extent of the lip of the step. Not for the first time has it been necessary to pull down part of a staircase and then fake it so that its end lengths will match up. This makes it necessary to use maximum precision and therefore all the attention, experience and skill of a specialist, which inevitably means money, i.e. , high cost. There are no known tools or devices for simplifying the handiwork of these specialists and making precision staircases, that is, for the operation of covering the staircase bore with slabs, placing them on the slope on which the prefabricated step parts lie. It is necessary for the specialist to craft the staircase painstakingly. Thus a tool has been conceived and designed to fill the vacuum in the field of staircase construction caused by the lack of any apparatuses or devices able effectively to substitute the many precise operations specialists are obliged to perform manually. DESCRIPTION OF THE INVENTION The tool proposed herein is a positioning device that guarantees perfect staircase modularity, that is, that step height and risers will always be uniform so that exact precision will exist throughout, from the bottom to the junction where the staricase's projection meets the upper floor. To be more specific, the tool herein invented operates by drawing on the horizontal plane of the first step, which is hand-laid by the specialist. Using the horizontal plane of this first step, step depth, the verticality of the riser or rear wall of the step and the difference in level between said first step plane and the next plane may be exactly regulated, one after another. Thus, as logically follows from the above statements, each step plane will serve as the reference for the next plane, up to crown of the staircase, which will lie perfectly flush with the plane of the upper floor. Structurally, the device is comprised of what may be considered two transversal racks, joined parallel to one another by a telescoping intervening longitudinal bar whose length may be adjusted to lengthen or shorten the distance between these two racks to match the length of the steps, or rather the width of the step. Each of the aforesaid racks features a surface designed to rest on the edge of the slab forming the horizontal plane of the first step, and a right-angle elbow bend at the other end, on which are mounted resting surfaces for positioning the step riser. Each of these right-angle elbow bends and the regulable components coupled to them constitutes a continuation, which are equipped in turn with an attachment which has the triple function of holding up the slab forming the plane for the next step, correcting the verticality of the riser slab, and marking the amount that the next step plane slab will have to protrude in order to make for precision in the building module. The surfaces for the edge of the first step's slab to rest upon are also equipped with attachement clips worked by screw spindles, which may be hand-cranked to grip the edge belonging to the first step plane. As said above, the slab or master slab that is going to constitute the horizontal plane of the first step will be set in place by hand, and after it is correctly leveled, the planned projection will jut out from its skirt (here skirt is taken to mean the first riser). The extendible longitudinal bar affixed to both of the transversal racks that form the aforementioned resting surfaces will ensure the correct parallel coplanar placement in any relative instance betweeen the maximum and the minimum; that is the transversal racks will alawys lie in the perfect flat position. Both the consolidation of the different telescoping parts of the elements described above and the vertical correction of the riser slab are achieved using threaded ram stems, which also include regulable stops for the overhang of the slab forming the plane. On one or both of these regulable stops, there are facilities for mounting a slide for side arms to mark the position of the step plane flank or staircase string if the staircase has one or both sides exposed and requires a handrail. Lastly, the longitudinal bar may be complemented with a hinge or circular sector which may be fixed to one of the racks to allow those stairs that swivel 90 º or follow a curved path to be arranged in modules along their angle or curve. DESCRIPTION OF DRAWINS In order to complement the description made herein and help provide a better understanding of the characteristics of the invention, attached to this descriptive report as an integral part hereof is a set of drawings giving a non-limiting illustration of the following: Figure 1. This is a side elevation diagram of a conventional staircase, which will serve as a reference for understanding the aims and working procedure to be followed using the positioner tool herein invented. Figure 2. This illustration provides an overall perspective of the positioner tool in its operating position, that is, set up on the slab forming the horizontal plane of a bottom step and the riser or rear vertical wall of that same first step. PREFERABLE EXECUTION OF THE INVENTION As shown in figure 1, it may be seen that a conventional staircase (1), whether arched or straight, is formed of a number of steps constituted by horizontal planes (2) which may, for example, be slabs. These slabs jut forward forming projections (3), while at the rear these horizontal planes (2) are complemented with vertical risers (4) which are also made up of slabs or any other suitable material. The total projection of the staircase is equal to the distance between the bottom point (6) of the staircase and its junction (7) with the upper floor (8). The total height of the staircase must be an exact multiple of a module, which is the exact distance between two horizontal planes (2) or steps; while the projection of the staircase must be an exact multiple of another module, which is the same as the distance between two consecutive vertical risers (4), or in other words, the distance between the riser of each step and the corresponding skirt of the first plane (2) of the step. The number of modules coincides in height and risers, and thus the staircase is perfect. Let us proceed now to figure 1, which clearly shows the positioner tool in place on a first step. This step is made up of the slab (2) forming the step's horizontal plane, featuring the bottom point (6) and the skirt (11) of this starting step, which corresponds with the vertical risers (4) of the following steps. It may be observed that the device as such is made up of a pair of twin racks (12) joined by a telescoping longitudinal bar (13), which is formed by two telescoping spans which may be held by a transversal screw (32) in such a way that the longitudinal bar (13) may be used to shorten or lengthen the distance between these two racks (12), depending on the width of the staircase or, in other words, the width of the step. The racks (12) are lain transversally, as shown in figure 2, and each of them includes a resting surface (14) that lies against the forward edge (15) of the slab (2). This resting surface (14) is complemented by a clamp (16) worked manually with a crank (17) that turns a screw spindle in the clamp (16), so the two clamps, one on each surface, form a means of gripping the forward or front edge (15) of the slab (2). On the end lying opposite the resting surface (14), each rack (12) has continuations (18) which bend at a right angle, each forming a vertical span (19) on which is mounted a telescoping element (20) whose extensibility may be regulated and which may be anchored with a screw (21). The elbow bends (19) and elements (20) forming the aforementioned continuations make a surface for the riser slabs (4) to rest upon, while the seats (22) fashioned as a prolongation bent in the opposite direction to the elements (20) mark the difference in level between the slabs On each prolongation forming the rests (22) referred to above are mounted regulable stops (23) provided to help position the front edge (15) of the slab (2) and thus define its projection out over the vertical riser (4) below. According to the construction described above, the tool is placed on the first step slab (2), as depicted in figure 2, with its surfaces (14) resting on the front edge (15) of this slab (2). The length of the racks (12) is then adjusted, thus finding the depth that the continuations (18) will have to reach, while the upper part (22) of the elements (20) that may be extended from the elbow spans (19) of these continuations (18) will form the seat for the projection of the second slab (2), belonging to the next step, thus forming the horizontal module (12) depicted in figure 1. As stated above, the clamps (16) are used to immobilize the tool assembly by gripping the front edge of the slab (2) in question so that the next riser slab (4) will be automatically positioned to rest on the surface formed by the vertical spans (19) and (20) of the elbow continuations (18). Logically, the correction or precision of the exact vertical line traced by the riser slab (4) will be determined by turning the stem (21), while the top slab's front edge (15) is positioned using the regulable stops (23), thus regulating their own projection over the riser or vertical slab (4). A slide housing (24) for each arm (25) is designed into one or both regulable stops (23). The arms (25) have an upper stop face (26) indicating the position of the side edge (27) of the slab (2). These arms (25) also include a square (28), which is also regulable and is for positioning the outer edge of the riser tablet (4) when the staircase has a cambered or face string. As is logical, this device is used in duplicate, one at each side, when the staircase rises with both sides open. The arms (25) may be regulated inside their slide guides (24) and immobilized using the correct screws (29), like the squares (28), which may be immobilized with their own screws (30). Lastly, the longitudinal bar (13) includes a compass (31) that is extremely important in making curved or turning staircases and is essential in cases in which the stair case is winding or runs along a curved or continuous path. Thus the positioner tool referred to above may be used on the horizontal plane (2) of the first step to obtain the step depth, the verticality of the riser slab (4) for that step, and the difference in level between that first horizontal step plane and the net horizontal plane, which will lie parallel to the first and will serve as a referene for all following step planes until the difference in level between the base plane and the upper floor (8) has been covered. Furthermore, the device herein invented may be used to find the projection between the edge (15) of the slab (2) and the plane of the riser slab (11), maintaining the distance of the riser slabs (1) in accordance with the module. Lastly, once the first step slab (2) has been placed, its support slabs (11) and all following support slabs (2) may be positioned exactly by merely resting them in the indicated areas and leveling each slab (2) in the traditional way, so the staircase takes impeccable shape. No further description is considered necessary in order for any expert on the subject to grasp the scope of the ivention and the advantages stemming from it. The materials, shape, size and arrangement of the elements may vary provided that the essence of the invention is not altered. The terms in which this report has been drawn up should always be taken in their broadest non-limiting sense.

Claims: Staircase jig wherein the jig is made up of two transversal racks (12) joined to one another by a telescoping longitudinal bar (13), the front end of each of these transversal racks (12) includes a surface (14) for abuttment against the front edge (15) of a first step, while at the other end of each rack (12) is an extendible extension (18), the rack defining thus the depth of the step, the extendible extensions (18) include a perpendicularly oriented vertical span (19) to the upper ends of which are attached elements (20) that telescope out laterally from the vertical span and comprises an upper part which constitutes a support for the projection of the next step, the elements (20) having forward prolongations on which are mounted adjustable stops (23) for abuttment against the front edge of the step, with the vertical spans of each rack (12) forming a support for the vertical riser (4) of the step. Staircase jig as set forth in claim 1, characterized in that the resting surfaces (14) are fitted with clamps (16) for gripping the front edge (15) corresponding with the horizontal plane (2) of the step, in order to inmobilize the assembly on this horizontal step plane (2), and said clamps (16) are designed to be operated by means of a screw spindle connected to a manually-turned outside crank (17). Staircase jig set forth in claim 1 and 2, characterized in that the telescoping longitudinal bar (13) joining the two racks (12) in parallel is complemented with a hinged compass (31) allowing steps to be set in spirals or along continuos curved paths. Staircase jig as set forth in the previous claims, characterized in that the regulable stops (23) resting on the front edge (15) are equipped with guides (24) for mounting side arms (25) provided with an upper stop (26) that positions the edge of the correct horizontal step plane (2), and these arms (25) also feature a square (28) which is regulable and is the means for positioning the outer edge of the vertical riser itself (4) in the case of stairs with outer strigs and handrails.

Inventors: QUINTANA VINOLAS ALBERTO, QUINTANA VINOLAS, ALBERTO
Applicants: QUINTANA VINOLAS ALBERTO, QUINTANA VINOLAS, ALBERTO
Application year: 1993
Main classification: E04F21
IPC codes: E04F21