Method and apparatus for anchoring hardwood floor systems

Abstract

A standoff sleeve/fastener assembly and a powered driver are provided for anchoring a subfloor component of a hard wood floor system to a concrete slab. The sleeve has a peripheral flange and a countersink at a first end. The fastener is disposed in the sleeve and has an enlarged head that is adjacent to but spaced from the first end of the sleeve. The driver has a nozzle with a striker bore sized to receive the head of the fastener and a recess sized to accommodate the peripheral flange of the sleeve. The subfloor component is anchored by (1) positioning the sleeve/fastener assembly in a hole in that component with the bottom end of the sleeve contacting the concrete slab, (2) positioning the driver nozzle so that the fastener head and the flange of the sleeve reside in its striker bore and recess respectively, and (3) operating the driver whereby its striker impels the fastener to (a) pierce and penetrate the concrete slab and (b) lock the sleeve between the concrete slab and the head of the fastener.

What is claimed is:  
     
         1 . Method for anchoring to a concrete base an attachment assembly for a wood floor wherein said attachment assembly comprises an attachment member that has top and bottom surfaces and having at least two holes each with a counterbore extending down from said top surface, and at least two compressible pads each having a top side and a bottom side with said top side contacting said lower surface of said attachment member, said method comprising the following steps: 
 (1) inserting (a) a sleeve having center bore, a distal end, a proximal end and a peripheral flange at said proximal end into each of said holes so that said peripheral flange resides in said counterbore and (b) a fastener having a distal end and a proximal end with an enlarged diameter head at said proximal end into each of said sleeves, with said distal end of said sleeve projecting below said attachment member by a predetermined amount so that it is substantially flush with the bottom side of said each compressible pad and with said head of said fastener extending above said proximal end of said sleeve;    (2) providing a manually operable pneumatic driver having a nozzle with an end surface that is sized to fit in said counterbore, a striker mounted for axial movement in a striker bore in said nozzle with said striker bore having a diameter at least equal to the diameter of said head of said fastener, and means for reciprocally driving said striker through (a) a rapid drive stroke whereby said striker is moved from an at-rest position in which the striker is withdrawn into said bore to an extended fastener-driving position in which said striker projects beyond said end surface and (b) a rapid return stroke whereby the striker is withdrawn from said fastener-driving position back to said at-rest position;    (3) positioning said driver so that said end surface of said nozzle resides within said counterbore and so that said fastener head resides in said bore; and    (4) operating said driver so as to cause said striker to impact said fastener head with a force sufficient to drive said fastener into said base far enough to cause the head of said fastener to (a) drive said flange into tight engagement with said attachment member and (b) force said sleeve into tight engagement with said base.    
     
     
         2 . Method according to  claim 1  wherein in step (1) the head of said fastener extends above said attachment member.  
     
     
         3 . Method according to  claim 1  wherein in step (4) the depth of penetration of said fastener into said base is limited by said sleeve.  
     
     
         4 . Method according to  claim 1  wherein said distal end of said fastener is substantially flush with said distal end of said sleeve prior to step 3.  
     
     
         5 . Method according to  claim 1  wherein said sleeve has a tapered countersink for said bore at said proximal end, and said fastener head has a conical side surface.  
     
     
         6 . Method according to  claim 5  wherein the angle of taper of said fastener is greater than the angle of taper of said countersink.  
     
     
         7 . Method according to  claim 6  wherein said countersink has a taper angle of about 60° and said conical side surface has a taper angle of about 82°.  
     
     
         8 . A fastener/standoff sleeve assembly for use in anchoring an attachment assembly for a wood floor to a concrete base, said assembly comprising: 
 a fastener having a shank with a distal end and a proximal end, a pointed tip at said distal end, and an enlarged diameter head at said proximal end, with said head having a side surface that is tapered inwardly; and    a sleeve for positioning said fastener in a hole in said attachment assembly, said sleeve having a distal end, a proximal end, a central bore that extends between said distal and proximal ends for accommodating the distal end of said shank, and a tapered countersink for said bore at said distal end of said sleeve, said countersink being shaped to accommodate said head of said fastener when said fastener is driven into said sleeve by an impact on said head while said sleeve is immobilized against axial movement.    
     
     
         9 . A fastener/standoff sleeve assembly according to  claim 8  wherein said fastener head has a conical side surface that has a taper angle greater than the angle of taper of said countersink.  
     
     
         10 . A fastener/standoff sleeve assembly according to  claim 8  wherein said fastener shank has a proximal relatively large diameter portion and a distal relatively small diameter portion, and said hole is sized to accommodate said distal relatively small diameter portion but not said proximal relatively large diameter portion.  
     
     
         11 . Method for anchoring to a concrete base a floor attachment assembly that comprises a floor attachment member having top and bottom sides, at least two compressible pads attached to the bottom side of said floor attachment member, and two holes extending through said attachment member, said method comprising the following steps: 
 (1) providing a fastener and sleeve assembly that includes a fastener having a shank with a leading end and a trailing end and a radially-projecting head at said trailing end, and a sleeve having an axial bore, a bottom end and a top end with a radially projecting flange at said top end, said leading end of said shank intruding into said axial bore;    (2) inserting said fastener and sleeve assembly into said one of said holes with said bottom end of said sleeve projecting below the bottom side of said attachment member and with the head of said fastener disposed above and spaced from the top side of said attachment member; and    (3) impacting said fastener head with a pneumatically-powered hammer with sufficient force to drive said fastener into said concrete base far enough to cause the head of said fastener to (a) force said flange into tight engagement with said attachment member and (b) anchor said attachment member to said base without compressing said pads.    
     
     
         12 . Method according to  claim 11  wherein in step (1) the head of said fastener extends above said attachment member.  
     
     
         13 . Method according to  claim 11  wherein in step (3) the depth of penetration of said fastener into said base is limited by said sleeve.  
     
     
         14 . Method according to  claim 11  wherein said sleeve has a tapered countersink for said axial bore at said proximal end, and said fastener head has a conical side surface.  
     
     
         15 . A fastener/standoff sleeve assembly according to  claim 8  wherein said sleeve has a peripheral flange at its said proximal end.  
     
     
         16 . A fastener/standoff sleeve assembly according to  claim 8  wherein said fastener has it shank inserted into said central bore of said sleeve, with said enlarged diameter head and the portion of said shank adjacent said head projecting from said proximal end of said sleeve.  
     
     
         17 . A fastener/standoff sleeve assembly according to  claim 16  wherein said fastener shank is gripped by said sleeve.  
     
     
         18 . A fastener/standoff sleeve assembly according to  claim 16  wherein said tip is substantially flush with said distal end of said sleeve.  
     
     
         19 . A fastener/standoff sleeve assembly according to  claim 18  wherein said sleeve has a peripheral flange at its said distal end and said enlarged diameter head of said fastener is spaced from said flange.  
     
     
         20 . A fastener/standoff sleeve assembly according to  claim 8  wherein said distal end of said sleeve has an end surface, said shank is stepped with a relatively large diameter portion extending distally from said head and a relatively small diameter portion extending between said tip and said relatively large diameter portion, and said relatively small diameter portion is disposed in said bore with said tip being substantially even with said end surface.