FR2548249A2 - Improvement to prefabricated concrete stairways - Google Patents

Abstract

The present invention relates to an improvement to prefabricated concrete stairways. According to the invention, each notch 3 of the string 1 has a rounded V-shaped cross-section at the point where the anchoring foot 4 is to be lodged. The underside of each step comprises a heel 6 provided with an inclined face 7 in contact with the upper ridge 8 of the riser 9. The plane passing through the inclined face is substantially perpendicular to the string in its mean position of inclination.

Description

The present invention relates to an improvement to straight staircases

  precast, concrete, as described in the applicant's main patent application, filed on

May 11, 1983.

  Prefabricated concrete staircases allow a significant gain both in terms of manufacturing and

laying on site.

  In the main patent application, a staircase is proposed, the stringer of which has transverse notches allowing the anchoring of market elements. The prefabricated market elements consist of a step with a perpendicular wall forming on the one hand the riser and,

  on the other hand, an anchoring foot positioned in the notches of the stringer.

  To increase the gains during manufacture, the present invention proposes an improvement to the stringer and to the steps elements so that the staircase can adapt to the different slopes that are encountered according to the uses, that is to say

  a staircase that is suitable for the pavilion entrance stairs, cellar 20 or others.

  According to the invention, each notch of the stringer has a V-shaped section rounded at the point. This rounding has a radius substantially equal to half the thickness of the anchoring foot so as to correspond to the rounding of the said anchor foot 25 thus allowing pivoting of the anchor foot, and therefore of

  the step element, in the corresponding notch.

  According to another arrangement of the invention, the bottom of each step has a heel obtained directly from the molding of the step element; this heel is provided with an inclined face 30 in contact with the edge of the rear upper end of the riser The plane passing through the inclined face is substantially

  perpendicular to the stringer in its average tilt position.

  The staircase portion shown by way of illustration in the appended drawing shows a stringer 1 and the tread elements 2 arranged on the stringer The stringer and the tread elements are prefabricated, preferably made of reinforced concrete The notches 3 are arranged transversely and are regularly spaced on the upper face of the stringer I; they are obtained by molding and have a V-shaped section with a rounding at the 40 point. This rounding, which corresponds to a portion of casing -2 of the cylinder to which the sides of the Vee forming the notch 3 are connected, receives the anchoring foot 4 of the walking element 2 The radius of the rounding is substantially equal to half the thickness of the anchoring foot 4 The said anchoring foot has its rounded lower end also to match the shape of the bottom of the notch 3 The opening of the V of the notch corresponds to the angle formed by the stringer I don its positions

tilt exterior.

  To maintain perfect horizontality of the steps 5 10 according to the inclinations of the stringer 1, the height between said steps 5 can vary and be kept constant by means of a heel 6 disposed under each step This heel 6 has an inclined face 7 in contact with the rear upper edge 8 of the riser 9 The talone obtained directly by molding, it extends over the entire lower part of the step The inclined face 7 of the heel is substantially flat, and it lies in a plane which is perpendicular to the average position of the stringer 1, that is to say between its maximum inclination and its minimum inclination When the stringer is at its lowest inclination, the step 5 rests on the riser 9; the edge 8 is in contact with the upper end of the inclined face 7 of the heel 6 The maximum inclination of the stringer is obtained when the edge 8 is located at the lower end of the inclined face 7 of the heel 6 L ' space 10 between the underside of step 5 and the upper part of riser 9 is filled with concrete to reinforce the base of step 5 on riser 9 The edge 8 of riser 9 can also be slightly rounded

  to avoid too much fragility.

  The invention is in no way limited to the embodiment indicated specially, but it also covers all possible variants provided that these are not in

  contradiction with the subject of each of the appended claims

to this description.

-3

Claims (5)

  1. Straight precast concrete staircase of the type comprising at least one stringer 1 and tread elements 2, the stringer 1 being provided with transverse notches 3 regularly distributed on the upper face of said stringer 1; the tread elements consisting of a tread 6 and a vertical wall to the said tread forming the riser 9 and an anchoring foot 4, characterized in that the section of the notches is V-shaped rounded at the tip.   2 straight prefabricated staircase according to claim 1 characterized in that the radius of the rounding of the notch 3 is substantially equal to half the thickness of the anchoring foot 4   and corresponds to the rounding of said anchoring foot.   3. Prefabricated straight staircase according to one of claims 1 and 2, characterized in that the underside of the step has a heel 6 provided with an inclined face 7 coming into contact with the edge 8 of the rear upper part of riser 9.   4. Prefabricated straight staircase according to claim 3, characterized in that the plane of the inclined face 7 is perpendicular to the stringer I in its average position of inclination.   5. Prefabricated straight staircase according to one of claims 1 to 4, characterized in that the space 10 between the step 5   and riser 9 is filled with concrete.