Patent Application
20060097128
There is in widespread use a plywood forming system, here referred to as the “1⅛″ plywood forming system”. This system consists of 1⅛″ thick plywood panels, typically 24″ wide by 8 feet high, reinforced with ¼″×2″ steel straps secured horizontally at regular intervals, to the ends of which are attached swinging steel latches which interconnect the individual panels into a continuous wall and also secure the flattened wire snap ties which hold the opposing panel wall assemblies in position against the hydrostatic force of the liquid concrete.
The panel latches are pivotally attached to the ends of the ¼″×2″ steel straps, herein called form panel bars, with hex head shoulder bolts, herein called panel bolts, and engage a similar bolt in the adjoining panel. Additionally, an extra bolt is usually applied to said form panel bars, which is available for attaching various brackets and stiffeners.
It is frequently desired to attach horizontal stiffening members, or walers, to the outside faces of the plywood form panels. These walers commonly consist of a 2″×4″ or 2″×6″ board and are generally held in position against the form by multiple brackets in the general form of a shelf bracket, with a vertical member to keep the waler approximately held against the form panels. Some prior art brackets have incorporated means of pressing the waler against the form panels, using wedges, cams, or other devices. For instance, U.S. Pat. No. 4,508,310 describes a waler, which incorporates an attached wedge, held in a receiving position for the waler by a keeper attached below the body of the waler.
The purpose of the present invention is to provide a waler bracket or clamp with an attached wedge for firmly holding the waler against the form panels, which is substantially easier to manufacture than prior art waler brackets. It is also the purpose of the present invention to provide a waler bracket in which the action of seating the waler and applying the wedging action is substantially easier and quicker than prior art versions. Previous designs have required that the device be assembled from several components by arc welding or other labor-intensive means. The likelihood of variation in the assembly of the individual parts tends to produce a product that is often functionally defective. The present invention lends itself to production techniques which have less variation and can be produced more efficiently. In one embodiment of the invention, the release of a wedge, and it's action can be initiated automatically by creating interference between the lower portion of the loose wedge and the wale member. This interference causes the wedge to rotate out of its raised position and drop down between a vertical lip of the bracket and the wale member, forcing it against the forming panels and bringing them into planar alignment.
In another embodiment of the invention, the vertical slotted portion of the bracket is extended a certain distance below the bottom of the form panel bar that the mounting stud bolt is attached, and is slightly offset towards the surface of the plywood form panel. When force is applied downward and outward on the bracket in normal use, the end of said vertical portion comes into contact with the surface of the plywood form panel, thus moving the fulcrum point of the arm further from the attachment stud, greatly increasing the strength and rigidity of the bracket and also preventing accidental rotation of the bracket longitudinally around the stud.
A notch 13 is depressed around a portion of its periphery 20, extending downwardly and outwardly to provide clearance for said stud while applying said bracket to said form panel bar.
