Inserts and method and apparatus for embedding inserts in cast members

Abstract

Method and apparatus for forming cast members having curved or flat walls. Steps are provided in the cast member by placing hollow plastic step inserts into holders provided along the inner core of a mold assembly or mounting inserts on reciprocating pins or mounting inserts to a marginal portion of the inner core. The cast material is then poured into the mold. The cast member, when set, is withdrawn from the mold assembly. In one embodiment, a holder portion of the step insert is broken away, leaving the step inserts embedded in the cast member to receive legs of manhole steps. The inserts are provided with flanges, preventing leakage of the cast material into the mold assembly. Similar seals are provided by other types of cylindrical-shaped inserts for use in wetcast and drycast fabrication methods. Mounting assemblies are also provided for holding inserts for embedment in planar walls.

1 . An apparatus for producing cast members having step inserts embedded therein for receiving legs of a step, comprising; 
 a mold assembly having inner and outer walls forming a hollow space defining a member to be cast;    one of said inner and outer walls having at least one mounting opening;    at least one insert member having a body portion and integral mounting portion inserted into said mounting opening for retaining the insert member on said mold assembly during a casting operation;    at least a portion of said mounting portion breaking away from the body portion when said cast member is separated from the mold assembly;    said main body portion being hollow and open at one end and having internal projections for force-fittingly receiving and holding one leg of the step member; and    said body portion including a sealing flange covering the mounting opening to prevent cast material inserted into the mold assembly from seepage therethrough.    
   
   
       2 . The insert of  claim 1  wherein mounting means comprises a plurality of flexible hook-like members for gripping a marginal portion of said opening and cooperating with said flange to retain said insert member in said opening.  
   
   
       3 . The insert of  claim 1  wherein said housing is provided with a plurality of annular flanges integral with and extending radially outwardly from said housing and spaced along the housing for retaining the insert in place when embedded in a cast member.  
   
   
       4 . The insert of  claim 1  wherein said closed end has an annular flange integral with said housing and extending radially outward therefrom to seal an opening in a mold core preparatory to insertion of the insert into a cast material.  
   
   
       5 . In combination, an insert and a reciprocatable pin assembly for receiving said insert for insertion into a casting material, said insert comprising: 
 a hollow, substantially cylindrical-shaped, elongated housing having an open end and a closed end;    one of said ends and having a flange lying in a plane diagonally aligned with a longitudinal axis of said housing;    another one of said ends having a flange lying in a plane perpendicular to said longitudinal axis;    said pin assembly having a first cylindrical-shaped portion of a first diameter;    a second cylindrical-shaped portion of a second diameter less than said first diameter, one end of said second portion being integrally joined to one end of said first portion, forming an annular ledge at the juncture thereof; said ledge lying in a plane perpendicular to a longitudinal axis of said pin assembly;    said pin assembly second portion being inserted into said insert through said open end with said open end resting on said ledge;    said pin assembly having an integral projection arranged on said ledge and extending along said second portion toward a free end thereof;    said insert having at least one slot extending inwardly from said open end for receiving said projection for aligning said insert on said pin assembly.    
   
   
       6 . A method for producing in a mold assembly a cast member having openings for receiving the legs of a step and employing a pin assembly and insert comprising: 
 (a) providing a pin assembly, said pin assembly having a first cylindrical-shaped portion of a first diameter;    a second cylindrical-shaped portion of a second diameter less than said first diameter one end of said second portion being integrally joined to one end of said first portion, forming an annular ledge at the juncture thereof; said ledge lying in a plane perpendicular to individual axis of said pin assembly; said pin assembly having an integral projection arranged on said ledge and extending along said second portion toward a free end and thereof;    (b) providing an insert having a hollow substantially cylindrical-shaped elongated housing having an open end and a closed end;    one of said ends and having a flange lying in a plane diagonally aligned with a longitudinal axes of said housing    another one of said ends having a flange lying in a plane perpendicular to said longitudinal axis; said insert having at least one slot extending inwardly from said open end for receiving said projection for aligning said insert on said pin assembly.    (c) placing said insert on said pin assembly second portion by inserting said second portion through the open end of said insert;    (d) sliding the insert onto said second portion until said open end engages said ledge;    (e) orienting said insert on said pin assembly to align said insert so that said slot receives said projection;    (f) projecting said pin assembly through an opening in said mold assembly and into casting material in said mold assembly; and    (g) withdrawing said pin assembly from the casting material, whereby said insert remains properly positioned in said casting material.    
   
   
       7 . An insert assembly adapted to be embedded in a cast member for force-fittingly receiving a leg portion of a step, said insert assembly being comprised of: 
 first and second members adapted to be telescopingly mounted to one another;    said first member comprising a hollow, substantially cylindrical-shaped elongated housing having first and second open ends and an integral annular flange intermediate said first and second ends, said flange being diagonally aligned to a longitudinal axis of said first member;    said second member comprising a hollow, substantially cylindrical-shaped elongated housing having a first closed end and a second open end;    said open end of said second member being telescopingly mounted upon one end of said first member, whereby the second member is force-fitted on said first member.    
   
   
       8 . The insert assembly of  claim 7  wherein said second member is provided with a plurality of outwardly extending integral flanges arranged at spaced intervals therealong to enhance embedment of the second member in a cast member.  
   
   
       9 . The insert assembly of  claim 7  wherein an interior surface of said second member has a portion thereof being provided with a plurality of annular projections extending radially inward; and 
 each projection having tapering cross-section.    
   
   
       10 . The insert assembly of  claim 7  wherein said first member has a portion of reduced thickness adjacent said diagonally-aligned flange to facilitate breaking away of a portion of the first member from said second member.  
   
   
       11 . The insert of  claim 10  wherein said portion of reduced thickness is obtained by scoring the first member.  
   
   
       12 . The insert assembly of  claim 7  wherein said first member is provided with a plurality of outwardly directed annular flanges for gripping an interior surface of said second member, the surfaces of said flanges being inclined so that it requires less force to telescopingly mount the second member onto the first member than is required to pull the first and second members apart.  
   
   
       13 . The insert assembly of  claim 7  wherein an interior of said second member is provided with a helical annular flange for gripping an exterior surface of said first member, the surface of said helical flange being inclined so that it requires less force to telescopingly mount the second member onto the first member than is required to pull the first and second members apart, said helical annular flange also serving to form a snug press-fit with a leg of a step member insertable therein.  
   
   
       14 . A method for embedding inserts in a cast member, said inserts being comprised of an assembly of first and second members adapted to be telescopingly mounted to one another; 
 said first member being a hollow, substantially cylindrical-shaped elongated housing having first and second open ends and an integral annular flange intermediate said first and second ends, said flange being diagonally aligned to a longitudinal axis of said first member;    said second member being a hollow, substantially cylindrical-shaped elongated housing having a first closed end and a second open end;    said open end of said second member being capable of being telescopingly mounted upon one end of said first member, said method comprising the steps of:    (a) providing a mold assembly including an annular-shaped core member having at least one opening and a tubular step tube joined to the core member and aligned with said opening and extending inwardly from a concave surface of said core member;    (b) inserting one end of said first member into a convex surface side of said core member and into said step tube, whereby said first member is force-fitted in said step tube, said first member being pushed into said step tube by a distance sufficient to move said diagonally-aligned flange adjacent to a marginal portion of said core surrounding the opening in said core; and    (c) telescopingly mounting said second member onto an end of said first member extending outwardly from the convex surface of said core, whereby said second member is force-fitted to said first member.    
   
   
       15 . The method of  claim 14  further comprising providing an annular-shaped area on said first member adjacent to said diagonally-aligned flange designed to enable the first member to easily break away from said second member when cast material, which is poured into the mold assembly, has set and the cast member is separated from said mold.  
   
   
       16 . A method for embedding inserts in a cast member, said inserts being comprised of an assembly of first and second members adapted to be telescopingly mounted to one another; 
 said first member being a hollow, substantially cylindrical-shaped elongated housing having first and second open ends and an integral annular flange intermediate said first and second ends, said flange being diagonally aligned to a longitudinal axis of said first member;    said second member being a hollow, substantially cylindrical-shaped elongated housing having a first closed end and a second open end;    said open end of said second member being adapted for being telescopingly mounted upon one end of said first member, said method comprising the steps of:    (a) providing a mold assembly including an annular-shaped core member having a pair of openings and a pair of cylindrical step tubes joined to the core member and each being aligned with one of said openings and extending inwardly from a concave surface of said core members that the longitudinal axis of said step tubes are substantially parallel;    (b) telescopingly mounting said second member onto one end of said first member, whereby said first and second members create a friction-fit therebetween; and    (c) inserting another end of said first member into a convex surface side of said core member and into said step tube, whereby said step tube and said other end of said first member creates a friction-fit therebetween, said first member being pushed into said step tube by a distance sufficient to move said diagonally-aligned flange adjacent to a marginal portion of said core surrounding the opening in said core.    
   
   
       17 . The method of  claim 16  further comprising providing at least one annular-shaped, diagonally aligned weakened area on said first member adjacent to said diagonally-aligned flange to enable an end of said first member holding said second member to easily break away from said other end of said first member at said weakened area when cast material, which is poured into the mold assembly, has set and the cast member is separated from the mold.  
   
   
       18 . A method for embedding inserts in a cast member, comprising: 
 providing first and second sets of holding pins, each set arranged along spaced intervals of an associated elongated support;    mounting an insert on each of said holding pins;    releasably securing said support along an exterior surface of a core member of a mold assembly with the support being aligned to position the holding pin sets in spaced, substantially parallel fashion; and    placing cast material in the mold assembly so as to embed the inserts into the cast material.    
   
   
       19 . The method of  claim 18  further comprising: 
 separating said core member from said cast member after the cast member has been set, thereby releasing the supports from said core member.    
   
   
       20 . The method of  claim 19 , further comprising: 
 prying the supports away from said cast member while said inserts remain embedded within the cast member.    
   
   
       21 . The method of  claim 20 , further comprising: 
 inserting cooperating legs of a step member into an associated pair of inserts.    
   
   
       22 . The method of  claim 18  further comprising: 
 providing at least one template having a pair of alignment edges; and    placing said supports along opposite sides of the template whereby one side edge of each support engages an associated one of said alignment edges to control the spacing distance between said supports and thereby controlling the spacing distance between the sets of holding pins.    
   
   
       23 . The method of  claim 22  wherein said template is further employed to maintain said supports in spaced parallel fashion.  
   
   
       24 . The method of  claim 22  wherein the step of placing the template between said supports further includes releasably securing the template to said core member.  
   
   
       25 . The method of  claim 24 , further comprising: 
 removing the template releasably mounted to the core after the supports have been aligned and before placing cast material into the mold assembly.    
   
   
       26 . The method of  claim 18  wherein the step of releasably mounting the supports to said core member further comprises: 
 providing a magnetized member on said core member having at least a surface portion upon which the supports are to be mounted; and    the step of providing said supports further including providing a member along a surface of said support opposite the surface from which the holding pins are mounted and which is magnetically attractive to said magnetized member for releasable mounting the supports to said core.    
   
   
       27 . The method of  claim 26 , further comprising: 
 providing a pair of templates each having a permanent magnet member on one surface thereof for placement against the core formed of a material which is magnetically attracted to the magnet members; and    placing said supports against opposite parallel edges of said templates to properly align said supports a given distance apart on said core.    
   
   
       28 . The method of  claim 27 , further comprising: 
 the step of removing the templates from said core after the supports have been properly aligned and before placing cast material into the mold assembly.    
   
   
       29 . An insert for receiving and supporting a leg of a step, comprising: 
 a hollow body closed at one end and open at an opposite end for force-fittingly receiving and supporting said leg;    an interior of said hollow body having a plurality of annular, spaced, inwardly directed projections for engaging and retaining the leg of the step therein; and    said interior further having plurality of substantially linear, axially aligned spaced projections located near said closed end and adapted for receiving and engaging a positioning pin inserted into the hollow interior preparatory to a casting operation to form a force fit with the positioning pin.    
   
   
       30 . The insert of  claim 29 , wherein said axially aligned projections terminate a spaced distance inwardly from said open end so as not interfere with a function of the annular projections provided for retaining said leg in said insert.  
   
   
       31 . In combination a plurality of inserts, insert positioning assemblies and an interior core of a mold assembly having at least one planar surface portion, comprising: 
 said insert positioning assemblies comprising first and second elongated supports having a plurality of holding pins arranged at spaced intervals along each of said supports;    said inserts each comprising a hollow shaped body having an open end for mounting on an associated one of said holding pins each inserted into one of said open ends;    each elongated support having a magnet assembly arranged on a surface of each elongated support opposite the surface upon which said holding pins are mounted;    said planar portion of said mold assembly inner-core having magnetically attractive means arranged therealong;    said elongated supports being placed upon said planar region and being magnetically attracted thereto; and    an alignment template provided with permanent magnet means along at least a portion of one surface thereof; and    said template having at least one pair of opposite parallel sides and being positioned on said inner core so as to be magnetically attracted to said magnetically attractive means and between and abutting adjacent sides of said elongated supports to properly position said supports in parallel fashion and at a given spacing.    
   
   
       32 . The combination of  claim 31  wherein said insert is provided with a hollow interior having annular projections to facilitate gripping of a leg of a step insertable into said hollow interior; and 
 a plurality of axially aligned spaced projections provided in a region extending from a closed end of said insert toward and terminating a spaced distance inward from said open end to provide a force fit with an associated positioning pin.    
   
   
       33 . The combination of  claim 31  wherein said permanent magnet means provided on said elongated supports comprises permanent magnet means embedded in a suitable plastic material.  
   
   
       34 . The combination of  claim 31  wherein said magnetically attractive means of said inner-core member comprises at least said planar portion of said core member being formed of a metal which is magnetically attractive to a permanent magnet.  
   
   
       35 . In combination a plurality of inserts, insert positioning assemblies and an interior core of a mold assembly having at least one planar surface, comprising: 
 said mounting assemblies comprising first and second elongated supports having a plurality of holding pins arranged at spaced intervals along one surface each of said supports;    said inserts each comprising a hollow shaped body having an open end for mounting on an associated one of said holding pins;    each elongated support comprising a magnetically attractive material;    said planar portion of said mold assembly inner-core having magnetic means arranged therealong;    said elongated supports being placed upon said planar region and being magnetically attracted to said magnetic means; and    an alignment template provided with magnetically attractive means along at least a portion of one surface thereof; and    said template having at least one pair of opposite parallel sides and being positioned on said inner core so as to be magnetically attracted to said magnetic means and between and abutting adjacent sides of said elongated supports to properly position said supports in spaced parallel fashion.    
   
   
       36 . An insert adapted to be embedded in a cast member for force-fittingly receiving a leg of a step, said insert comprising: 
 a hollow, substantially cylindrical-shaped elongated housing having an open end and a closed end;    one of said ends having a flange lying in a plane diagonally aligned with a longitudinal axis of said housing;    an interior surface of said housing having a portion thereof being provided with a plurality of projections arranged at spaced intervals and extending radially inward to facilitate gripping of said leg.    
   
   
       37 . The insert of  claim 36  further comprising: 
 a holding portion projecting away from the housing for engaging an opening in a support member for retaining the insert on the support member.    
   
   
       38 . The insert of  claim 36  wherein said flange at said open end covers a marginal portion surrounding an opening in a support member for retaining the insert on the support member and to prevent seepage of a cast material therethrough.  
   
   
       39 . The insert of  claim 36  wherein said housing is provided with a second plurality of flanges extending radially outwardly from said housing and spaced along the housing for retaining the insert in place when embedded in a cast member.  
   
   
       40 . The insert of  claim 36  wherein said closed end seals an opening in a mold core of a mold assembly preparatory to insertion of a cast material into the mold assembly.  
   
   
       41 . The insert of  claim 36  wherein each of the plurality of projections have a tapering cross-section defined by first and second sides transverse to the longitudinal axis.  
   
   
       42 . The apparatus of  claim 1  wherein said projections are arranged at spaced intervals and extend radially inward.  
   
   
       43 . The apparatus of  claim 1  wherein each of the internal projections have a tapering cross-section defined by first and second sides transverse to the longitudinal axis.  
   
   
       44 . The apparatus of  claim 1  wherein said projections are annular projections arranged at spaced intervals and extend radially inward.  
   
   
       45 . A method for embedding inserts in a cast member, said inserts being comprised of a hollow, substantially cylindrical-shaped elongated support portion, a hollow, substantially cylindrical-shaped elongated insert portion having interior projections for gripping a leg of a step and a diagonally aligned flange between said holding portion and said insert portion;  
     said method comprising the steps of: 
 (a) providing a mold assembly including an annular-shaped core member having at least one opening and a tubular step tube joined to the core member and aligned with said opening and extending inwardly from a concave surface of said core member; and  
 (b) inserting one end of said holding portion into a convex surface side of said core member and into said step tube, whereby said first member is force-fitted in said step tube, said holding portion being pushed into said step tube by a distance sufficient to move said diagonally-aligned flange adjacent to a marginal portion of said core surrounding the opening in said core.  
 
   
   
       46 . The method of  claim 45  further comprising providing at least one annular-shaped, diagonally aligned weakened area adjacent to said diagonally-aligned flange; 
 placing cast material into the mold assembly; and    separating the cast member from the mold assembly causing the holding portion to break away from the insert portion along said diagonally aligned weakened portion; and    inserting the leg of the step into said insert portion.    
   
   
       47 . The combination of  claim 31  wherein said magnet assembly comprises a plurality of permanent magnets arranged in recesses in said opposite surface; and epoxy material for retaining said magnets in said recesses.