Abstract:
A self-locking outside corner pad of sheet material and adapted for use with thin rectangular objects such as window frames or doors. The pads have adequate thickness and suspension structure to allow stacking, even without an outer sleeve.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This disclosure relates generally to corner protectors made from paperboard or the like, and more particular to those adapted for use with rectangular objects such as windows or doors. 
     2. Description of the Prior Art 
     Pads of the type described have typically been simple multiple folds of scored sheets to provide satisfactory thickness in six sections as shown in U.S. Pat. No. 2,896,833 to Markham. Other designs employ multiple materials such as in U.S. Pat. No. 2,885,139 to Werner et al. There is a need for a lightweight, self-locking pad of one material which is easy to assemble yet provides improved protection for the corners of objects of the general character described. 
     SUMMARY OF THE INVENTION 
     A one-piece corner pad with double thickness side walls and hollow cells at right angles to fit on the corner of a window frame or door. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an assembled pad embodying the present invention; 
     FIG. 2 is a plan view of a blank adapted to be erected into a pad similar to that shown in FIG. 1; 
     FIG. 3 is a perspective view of the blank shown in FIG. 2 partially erected and illustrating the assembly of the relative parts of the blank; 
     FIG. 4 is a perspective view of the pad further illustrating the relative position of the individual parts of the blank shown in FIG. 2; 
     FIG. 5 is a side elevation section view of the pad shown in FIG. 1 taken along section lines 5--5; 
     FIG. 6 is a sectional elevational view of a portion of the pad shown in FIGS. 1 and 5 taken along section lines 6--6 in FIG. 5; 
     FIG. 7 is a plan view of a window frame fitted with pads such as those shown in FIG. 1; 
     FIG. 8 is a perspective view of one of the pads and a portion of the frame shown in FIG. 7 more closely illustrating the relationship between the frame and the pad; 
     FIG. 9 is a plan view of an alternate embodiment showing a window frame with four corner pads fitted into recess slots in the pad; 
     FIG. 10 is a perspective view of a portion of the window frame shown in FIG. 9 more closely illustrating the position of the frame into the recessed areas of the pad. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     This invention is for a pad which has a particular structure and configuration so that it may be used on the outside corners of rectangular objects to be shipped such as mirrors, doors, window frames, or other similar objects where protection must be afforded not only from blows on the edge or corner of the object but also to the sides near the corner where the pad may be located. The pad 10 is erected from a blank 11 which is shown generally in FIG. 2 and which is manufactured from foldable sheet-like material such as corrugated paperboard and has two rectangular outer wall panels 12 and 13 which are separated by a vertical fold line 14 and are adapted to lie at right angles to one another as can be seen best in FIG. 3. First and second side wall panels 15 and 16 are connected to the outer wall panels 12 and 13 along horizontal fold lines 17 and 18, respectively. These side wall panels are adapted to lie in overlapping relationship as seen in FIG. 3 to provide a double thickness side wall for the pad 10. 
     Although other techniques may be used, the particular embodiment shown illustrates the use of a U-shaped line cut 19 in the horizontal fold line 18 which is adapted to receive a locking tab 20 which is hingedly connected to the vertical edge of the side wall 15 along a short fold line 21 and projects into the adjacent side wall 16, the tab being die cut therefrom. It may be seen in FIG. 3 that when the outer panels 12 and 13 are folded into right angle relationship and the side walls 15 and 16 are placed in overlapping relationship, the locking tab 20 serves to hold the assembly in that position. 
     A similar structure is located on the opposite side of the two outer wall panels 12 and 13 and include side wall panels 22 and 23 connected along hinge lines 24 and 25 with a locking tab 26 connected along a hinge line 27 and adapted to be inserted through a line cut 28 in the fold line 25. At the outer lateral edges of the two adjacent outer wall panels 12 and 13 are rectangular spacer panels 29 and 30 connected along vertical hinge lines 31 and 32. The spacer panels 29 and 30 are positioned at right angles in the final folded configuration to the adjacent outer wall panels 12 and 13, respectively. The purpose of these spacer panels 29 and 30 is to position the inner wall panels 33 and 34, which are connected along vertical fold lines 35 and 36 from the adjacent parallel outer wall panel 12 or 13, respectively. 
     Connected to the top and bottom edges of the spacer panels 29 and 30 along parallel fold lines are spacer tabs 37, 38, 39 and 40. The top and bottom edges of the two spacer panels 29 and 30 are inset slightly so that the fold lines 41, 42, 43 and 44 are slightly inside the spacing of the fold lines 17, 24 and 18 and 25 which allows these spacer tabs as seen in FIG. 4 to be positioned on the inside of the side walls to provide additional strength and support to the inner walls 33 and 34 which lie on top of those spacer tabs. Additional rigidity and the final locking feature is obtained with an additional pair of flaps 45 and 46 which are connected to the outermost lateral edges of the blank along vertical fold lines 47 and 48 and come together in diagonal abutting relationship as seen best in FIG. 5 to lock the inner wall panels in position and provide additional strength to the structure. 
     It should be noted that where a particular frame crossection includes a narrow flange, such as 49 on the window frame 50, seen best in FIG. 8, a slot 51 may be formed in each of the two inner wall panels 33 and 34 to accommodate that flange. Alternatively, the inner wall panels 33 and 34 may be notched to permit the frame 52 as seen in FIG. 10 to fit into the pad 10 and give even greater protection from the sides of the pack.