Manhole lift insert with frangible positioner

Abstract

A manhole lift insert with a socket portion and a frangible portion that is inserted in a pre-positioned bushing in the outer wall of a manhole form. A key in the sleeve portion may be received in a keyway in the bushing in the form wall so that the insert is properly oriented in the form.

1 . A frangible manhole lift insert, comprising: 
 (a) a socket, wherein the socket comprises a hole at a first end, the hole adapted to receive and retain a lift in a releasable manner;    (b) a frangible member, the frangible member adapted to be located at least partially in an aperture formed in a form wall, the frangible member joined to the socket proximate to the first end of the socket at a frangible region, wherein applying a shearing stress proximate to the frangible region separates the socket from the frangible member.    
   
   
       2 . The frangible manhole lift insert of  claim 1 , wherein the frangible member further comprises a plurality of ribs extending from an outer surface of the frangible member.  
   
   
       3 . The frangible manhole lift insert of  claim 2 , wherein the plurality of ribs are oriented substantially parallel to one another.  
   
   
       4 . The frangible manhole lift insert of  claim 3 , wherein the plurality of ribs are oriented substantially parallel to a longitudinal axis of the socket.  
   
   
       5 . The frangible manhole lift insert of  claim 1 , wherein the member further comprises a key extending from the outer surface of the frangible member, the key adapted to interact with a keyway associated with the form to orient the socket in a desired orientation.  
   
   
       6 . The frangible manhole lift insert of  claim 5 , wherein the key is adapted to interact with a keyway in a bushing associated with the aperture in the form wall.  
   
   
       7 . The frangible manhole lift insert of  claim 1 , wherein the socket and frangible member are formed as a single piece.  
   
   
       8 . The frangible manhole lift insert of  claim 1 , wherein the socket and frangible member are formed as two separate pieces and wherein a frangible joiner joins the two pieces together.  
   
   
       9 . The frangible manhole lift insert of  claim 1 , wherein the lift insert further comprises a collar extending from a portion of the frangible member.  
   
   
       10 . The frangible manhole lift insert of  claim 9 , wherein the collar extends from a portion of the frangible member proximate to the socket.  
   
   
       11 . The frangible manhole lift insert of  claim 9 , wherein the collar extends from a portion of the frangible member distal to the socket.  
   
   
       12 . A method of including a lift insert in a concrete structure in a desired location and orientation, comprising: 
 (a) providing a concrete form, the concrete form comprising at least a first form wall and a second form wall, interior surfaces of the first and second form walls oriented with respect to one another to define a void, the first form wall further defining at least one aperture;    (b) locating a frangible insert in the first form wall aperture such that a frangible region of the insert is proximate the interior surface of the first form wall;    (c) depositing a quantity of casting material into the void;    (d) allowing the casting material to cure; and    (e) removing the form walls from the cured casting material such that a portion of the frangible insert shears off to expose a socket portion of the frangible insert, the socket portion defining a hole at a first end, the hole adapted to secure a lift in a releasing manner.    
   
   
       13 . The method of including a lift insert in a concrete structure in a desired location and orientation of  claim 12 , further comprising locating a bushing in the first form wall aperture, the bushing interacting with portions of the frangible insert to locate the frangible insert in a desired location and orientation with respect to the first form wall.  
   
   
       14 . The method of including a lift insert in a concrete structure in a desired location and orientation of  claim 13 , wherein locating the bushing in the first form wall aperture further comprises locating the bushing in the first form wall aperture such that a keyway of the bushing is located to interact with a key on the frangible insert to orient the frangible insert in a desired manner.