The Burke Company

Jack A Holt

Philip A Torbet

Robert L Lathrop, Jr

A remotely releasable hoisting coupling for engagement with an anchor cast in place within a concrete slab. The anchor provides a passage opening through the surface of the slab and an annular abutment shoulder spaced beneath said surface. The coupling comprises a body insertable into the anchor, a pair of lugs supported in the body at diametrically opposed positions for rocking movement about a diametric axis extending normal to the body, and means to selectively move the lugs between a protruding condition engaged with the abutment shoulder and a retracted condition disengaged from the shoulder. The means to selectively move the lugs comprises a rod axially moveable within the body and having cam surfaces directly engagable with the lugs to force the lugs to the protruding condition and holding surfaces to maintain the lugs in the protruding condition, without loading the cam surfaces. A lifting bail is carried by the body for pivotal movement about an axis extending parallel to the diametric axis of the lugs.

Hoisting coupling for concrete slabs

A lifting anchor for incorporation into a poured concrete slab. The anchor comprises a steel sleeve having an irregular exterior surface to effect a bond between the sleeve and the concrete of the slab and an interior surface defining a cylindrical opening formed with an annular abutment. During pouring, concrete is excluded from the interior of the sleeve opening by a plastic cap clipped onto the exterior of the bottom end of the sleeve and a plastic plug telescoped into the upper end of the sleeve. After formation of a slab with the anchor in place, the plug is removable to afford access to the interior of the sleeve. A hoisting coupling is engagable with the anchor through means of a cylindrical body sized for entry into the sleeve. The inner end of the body is provided with a pair of lugs which can be extended radially outward to engage the abutment of the sleeve and contracted radially inward to afford removal of the body from the sleeve. The lugs are selectively movable between the extended and retracted positions through means of an actuating rod extending axially of the body. The outer end of the actuator rod has a device for applying tension thereto so as to permit disengagement of the lugs from the abutment from a remote location. A hoisting bail is secured to the exterior of the coupling to enable the coupling to be engaged by the lifting hook of a crane.

Lift system for concrete slabs

A joint clamp particularly useful in joining braces of the type used temporarily to brace concrete slabs employed in tilt-up construction. The clamp can be installed onto a cylindrical brace without the employment of tools and without access to either end of the brace. It comprises, as a principal component, a tubular member that defines an opening having a generally cylindrical cross-section corresponding to the cross-sectional size of the brace. The wall forming the cylindrical opening is formed with a helically extending slot having a width, in an oblique direction, slightly larger than the cylindrical brace so that the clamp can be placed on the brace in an oblique position and then twisted into parallelism with the brace to snugly embrace the brace. The tubular member carries one or more secondary clamps for securing cooperating secondary brace members thereto.

Joint clamp for joining intersecting brace members and method for making

A hanger comprising a pair of cast ends secured to one another by a tie rod having enlarged upset heads disposed for engagement with ends. The ends also include shoulders disposed beneath the rod for abutting engagement with an element upon which the hanger is supported. In use, the hanger is supported on a support element with the rod spanning the element and the shoulders engaged with opposite sides of the element. As thus positioned, loads imparted to the ends apply tension to the tie rod and compression to the support element.

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Belmont, CA, United States of America

Jack A Holt