Apparatus for lifting concrete panels

Abstract

An apparatus for lifting precast concrete panels includes a lifting body having a forward portion adapted to engage in an anchor head, a latch yoke pivotally connected to a rearward end of the lifting body and including a safety latch cooperating with the forward portion .Iadd.of the lifting body .Iaddend.to lock an anchor head to the forward portion, a release yoke pivotally attached to the lifting body .Iadd.for movement between locked and release positions .Iaddend.and including a cam .[.roller for urging.]. .Iadd.effective during movement of the release yoke to its release position to cause .Iaddend.the latch yoke to pivot to a release portion, and a lifting bail pivotally attached to the forward portion. The .[.lifting body.]. .Iadd.release yoke .Iaddend.includes a safety pin block extending .[.upwardly.]. from a rearward portion thereof adjacent .[.to.]. the rearward end of the latch yoke. The latch yoke and safety pin block include bores which are in registry with each other when the apparatus is oriented to a locked position. A safety pin is inserted into the bores and prevents relative pivotal movement between the latch yoke and .[.lifting body.]. .Iadd.release yoke.Iaddend., and is removable from the bore by a lanyard which is pulled by a worker.

What is claimed is: 
     
       1. In an apparatus for lifting precast concrete panels of the type including a lifting body having a forward portion adapted to fit within an anchor recess and engage an anchor head, a latch yoke .[.pivotally connected.]. .Iadd.having a pivot connection .Iaddend.to a rearward end of said lifting body .Iadd.for movement between locked and release positions .Iaddend.and including a safety latch .Iadd.at a forward end thereof .Iaddend.cooperating with said forward portion .Iadd.of said lifting body .Iaddend.to lock an anchor head to said forward portion when said latch yoke is pivoted to .[.a.]. .Iadd.said .Iaddend.locked position, a release yoke pivotally attached to said lifting body .Iadd.for movement between locked and release positions with respect to said latch yoke .Iaddend.and including .Iadd.cam .Iaddend.means .[.for urging.]. .Iadd.effective during movement of said release yoke from said locked position to said release position thereof to cause .Iaddend.said latch yoke to pivot to .[.a.]. .Iadd.said .Iaddend.release position .Iadd.thereof .Iaddend.wherein said safety latch is displaced from said forward portion, and a lifting bail pivotally attached to said forward portion, the improvement comprising: .Iadd.locking .Iaddend.means extending between a rearward end of said latch yoke and .[.said.]. .Iadd.a .Iaddend.rearward end of said .[.lifting body.]. .Iadd.release yoke.Iaddend., and positioned rearwardly of said .[.urging.]. .Iadd.cam .Iaddend.means and said pivot .[.connections.]. .Iadd.connection .Iaddend.between said lifting body.[.,.]. .Iadd.and .Iaddend.latch yoke, .[.and release yoke, for.]. preventing pivotal movement of said latch yoke relative to said lifting body when said .[.latch.]. .Iadd.release .Iaddend.yoke is in said locked position .Iadd.thereof.Iaddend., thereby locking said apparatus to said anchor head.   
     
     
       2. The apparatus of claim 1 wherein said .[.pivot preventing.]. .Iadd.locking .Iaddend.means includes a pair of bores formed in said latch yoke and said .[.lifting body.]. .Iadd.release yoke.Iaddend., said bores being positioned to be aligned with each other when said .[.latch yoke is.]. .Iadd.yoke are .Iaddend.in said locked position .Iadd.thereof.Iaddend.; and a safety pin sized to be removably inserted into said bores, thereby providing a rigid connection between said latch yoke and said lifting body and preventing relative pivotal movement therebetween. 
     
     
       3. The apparatus as claim 2 wherein said release yoke includes a safety pin block extending .[.outwardly.]. therefrom .[.adjacent to.]. .Iadd.toward .Iaddend.said rearward end of said latch yoke and including one of said bores. 
     
     
       4. The apparatus of claim 3 wherein said safety pin block bore includes detent means for retaining said safety pin therein. 
     
     
       5. The apparatus of claim 4 wherein said bores, when aligned together form a combined bore extending .[.rearwardly and angled outwardly from said apparatus.]. .Iadd.through said safety pin block into said latch yoke in a direction inclined toward said lifting body.Iaddend.. 
     
     
       6. The apparatus of claim 5 wherein said safety pin block is fixed relative to .[.a remainder of.]. said release yoke. 
     
     
       7. In an apparatus for lifting precast concrete panels of the type including a lifting body having a forward portion adapted to fit within an anchor recess and engage an anchor head, a latch yoke .Iadd.having a rearward end .Iaddend.attached to a rearward portion of said body at a first pivot connection .Iadd.for movement between locked and release positions .Iaddend.and including a safety latch cooperating with said forward portion .Iadd.of said body .Iaddend.to lock an anchor head to said forward portion when said latch yoke is pivoted to .[.a.]. .Iadd.said .Iaddend.locked position, a release yoke connected at a midportion thereof .[.of.]. .Iadd.to .Iaddend.said rearward portion of said body at a second pivot connection forward of said first pivot connection .Iadd.for movement between locked and release positions .Iaddend.and including cam means, located forward of said second pivot connection, .[.for urging.]. .Iadd.and effective during movement of said release yoke from said locked position to said release position thereof to cause .Iaddend.said latch yoke to pivot to .[.a.]. .Iadd.said .Iaddend.release portion .Iadd.thereof .Iaddend.wherein said safety latch is displaced from said forward portion, and a lifting bail pivotally attached to said forward portion .Iadd.of said lifting body.Iaddend., the improvement comprising: said latch yoke including a first bore in .[.a.]. .Iadd.said .Iaddend.rearward end thereof;   said .[.lifting body.]. .Iadd.release yoke .Iaddend.including a safety pin block extending .[.upwardly from a rearward end of said rearward portion.]. .Iadd.therefrom on the opposite side of said second pivot connection from said cam means toward said latch yoke .Iaddend.and including a second bore.[.,.]. located to be aligned with said first bore when said .[.apparatus.]. .Iadd.release yoke .Iaddend.is in said locked position.[.,.]. and forming with said first bore a combined bore .[.angled rearwardly and upwardly from said apparatus.]. .Iadd.extending into said yokes in a direction inclined toward said lifting body.Iaddend.;   a safety pin sized .[.to slidably engage.]. .Iadd.for slidable engagement within .Iaddend.said combined bore, thereby preventing relative pivotal movement between said latch yoke and said lifting body; and   detent means for releasably retaining said safety pin within said combined bore.