Arrangement for stairs of concrete for attainment of reduced step noise
United States Patent 191 Thorsnes 1 Apr. 8, 1975 1 1 ARRANGEMENT FOR STAIRS OF CONCRETE FOR ATTAINMENT OF REDUCED STEP NOISE Ola Oystein Thorsnes, Oslo, Norway [52] 11.5. CI 52/189; 52/403 [51] Int. Cl ..E04f 11/14 [58] Field of Search 52/182, 189, 179, 181, 52/191, 396, 403; 182/10 D, 189  
 [56] References Cited UNITED STATES PATENTS 710,880 10/1902 McDonald 52/254 1,265,949 5/1918 Osborn 52/189 1,622,739 3/1927 Rosenblum et a1... 52/179 1,861,751 6/1932 Nicols 52/189 1,985,143 Buffaloe 52/189 2,094,782 10/1937 Doherty 52/254 X 3,107,377 10/1963 Nathan 52/403 X 3,1 14,940 12/1963 Rockabrand et al. 52/403 X FOREIGN PATENTS OR APPLICATIONS 1,960,982 6/1970 Germany 52/189 Primary E.ranzinerPrice C. Faw, Jr. Attorney, Agent, or FirmLarson, Taylor &amp; Hinds [57] ABSTRACT Concrete stairs are designed for attainment of reduced step noise. The stairs comprise a central trunk supported in the building on pads of elastic material, the trunk being formed as a unit with vertical and horizontal flats, with prefabricated steps being attached to the horizontal flats on inserts consisting of pads of elastic material. The steps may be anchored by bolts extending through relatively enlarged holes in the trunk, with an elastic insert between the head of the bolt and the trunk surrounding the hole.  
 5 Claims, 2 Drawing Figures ARRANGEMENT FOR STAIRS OF CONCRETE FOR ATTAINMENT OF REDUCED STEP NOISE The present invention relates to an arrangement for stairs of concrete for attainment of reduced step noise, said stairs being of the kind where sound-deadening means are inserted between each step and the supporting structure for the steps.  
  For such stairs, it is suggested in accordance with the invention that the stairs comprise a central trunk supported in the building on pads of elastic material, said trunk being formed as a unit with vertical and horizontal flats, and that prefabricated steps are attached to the horizontal flats with inserts in between consisting of pads of elastic material which are known per se.  
  In accordance with one embodiment of the invention, it is suggested that the attachment of the steps is done by means of screw bolts which are anchored in the plates at the upper end and extend through holes in the trunk, said holes having considerably larger diameter than the bolts, whose lower ends, which are furnished with heads or nuts, are fastened to contact plates or washers or the like which rest against the body of the trunk with an elastic insert in between.  
  The invention will be explained more closely with reference to the drawing which shows an embodiment of concrete stairs for use in a stairway where it is important to reduce step noise, FIG. 1 being a detail in crosssection, and FIG. 2 showing a full set of stairs in section.  
  The stairs comprise a central, wide trunk l, for example about 60 centimeters wide, and floating steps 2. The trunk, which is supported on an elastic material like neopren pads 3, 4, is put in place as soon as the carcassing is finished and serves as stairs during the continued building process. When the rough work is finished, prefabricated steps 2 are installed on elastic material like neopren pads 5, 5. In accordance with the embodiment on the drawing, the steps are bolted and neopren pads 8 are inserted between the heads 7 of the bolts 6 and the trunk l of the stairs. There is considerable clearance 9 between the bolt 6 and the trunk 1, and the bolt 6 is purposely installed at a certain angle with the step 2 for the purpose of pulling the step into good contact and for reducing the vertical component of the forces transmitted through the bolt.  
  The step is preferablylcovered with a soft material 10 on the top surface, for example P.V.C. with elastic underlay.  
  The step is advantageously made as follows: An upper bead which runs along one long side and both short sides of the step is first cast in a form. The elastic top surface cover 10 and the step nose 11 which is made of a somewhat stronger material, are then inserted into the form, and thereafter the form is filled with reinforcing material and concrete for the final forming of the step. When the nose is inserted, rivets or the like 12 are also arranged which hold the nose when cast in. The nose can also be held by embedding a protruding bead or the like in the concrete.  
  During casting of the step, a bushing 13 for fastening the bolt is put in place.  
 I claim:  
  1. A concrete stair arrangement comprising a central trunk formed with stepped horizontal and vertical flats for supporting step members, said central trunk being supported by building structure, step members supported by said horizontal flats, sound deadening means between each of said step members and its supporting horizontal flat, a layer of elastic material on the upper surface of each step member, a layer of elastic material between said central trunk and each area where it is supported by building structure, at least one bolt secur: ing each step member to its supporting flat on said central trunk, each bolt being secured at it supper end in its associated step member and extending downwardly with substantial clearance through a bore formed in said central trunk, head means at the lower end of the bolt for bearing against the trunk about the lower end of said bore to hold the step member firmly secured to the trunk, said head means including a layer of elastic material bearing directly against the trunk surface about the lower end of the bore.  
  2. Apparatus as claimed in claim 1 wherein said bolt is threadedly engaged at its upper end in said step member, and said head means comprises a bolt head and an elastic pad about the bolt adjacent the head.  
  3. Apparatus as claimed in claim 1 wherein said bolt is oriented at an acute angle to the horizontal such that tightening thereof urges the step member downwardly onto its horizontal flat and laterally toward its adjacent vertical flat.  
  4. Apparatus as claimed in claim 3 wherein said central trunk is supported at its ends by building structure so as to be suspended therebetween, and layers of elastic material are provided between the ends of the trunk and the building structure.  
  5. Apparatus as claimed in claim 4 wherein said bore opens into a horizontal flat inrsaid trunk, and extends downwardly therefrom at an acute angle to the horizontal,&#39;the lower end of said bore being readily accessible from the underside of said central trunk.