Patent Publication Number: US-6338216-B1

Title: Interlocking crossbar easel

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Provisional patent No. 60/113,125, filed Dec. 21, 1998. 
    
    
     BACKGROUND— 
     Field of Invention 
     This invention relates to an easel for supporting standard canvas, drawing boards and displays by means of an interlocking crossbar. 
     Description of Prior Art 
     Art students are in need of a sturdy, low cost, lightweight, disposable painting easel that they can easily carry to class. 
     The following criteria are not currently available in one complete easel form: 
     1. An easel that can be secured from the top by use of a crossbar that interlocks with the easel to firmly hold a standard canvas or display in place. 
     2. An easel that can securely hold a canvas or display up to twenty-four inches in height as well as the six other standard sizes. 
     3. An easel that can be made of low cost material such as cardboard or flexible plastic for disposability. 
     4. An easel that is lightweight for ease of portability to painting classes, conventions, in the field painting and the like. 
     The following relevant prior art patents are noticed: US patents; U.S. Pat. No. 5,388,798 Glick; U.S. Pat. No. 5,058,850 Glick; U.S. Pat. No. 5,660,365 Glick; U.S. Pat. No. 4,512,541 Lietzke. 
     None of the prior art patents, uncovered in the search, disclosed an easel with all of the following characteristics. An easel designed for the use of both painting canvases and displays. An easel designed to employ the use of a top crossbar to secure the easel and the object in place. An easel that employs an interlocking crossbar to secure seven standard painting canvas sizes as high as twenty-four inches. 
     Glick in U.S. Pat. No. 5,388,798 uses a pyramidal form easel with the bottom front side edges turned up into hook like supports. These bottom hooks are intended to be the only mechanism securing the displayed object in place. This easel does not contain a self-support that would hold the easel&#39;s side walls from moving in or out. 
     Glick in U.S. Pat. No. 5,058,850 uses a pyramidal form easel that employs interlocking grooves on the lower front sides of the easel. The grooves allow the easel to interlock into of a specifically designed frame. This easel can not hold a display other than the frame designed to attach to the easel. 
     The U.S. Pat. No. 5,660,365 Glick easel design has a main front panel with side supports on each end designed to hold the easel upright. The front panel has hooked feet that support an object only from the bottom edge. The object lies against the inclined panel. The object is not secured to the easel from the top in any manner. The side panels of the easel are not as supportive as a triangle shaped base. 
     U.S. Pat. No. 4,512,541 Lietzke illustrates the use of a platform base and back panel designed to hold an article of merchandise to be displayed. This easel does not have proper back support to hold a painting canvas. The easel does not have any method of securing a display to the easel. 
     SUMMARY OF THE INVENTION 
     The invention comprises the following combination of features: This easel is preferably made of a flat sheet of cardboard, flexible plastic or the like. Other material such as wood, metal or ridged plastic may be used with the use of common hinges rather than folds upon lines of weakness. The easel body is formed from an isosceles triangle shape that has a line of weakness in the center that allows the shape to be folded. The easel body stands vertically as two substantially right triangular side panels. Both sides preferably have at least eight notches in them. The notches are spaced apart at specific dimensions that correspond with seven standard canvas sizes. The second piece to the easel, referred to as the top crossbar, spans across the front opening of the easel body. The crossbar preferably has at least four notches on one edge of the two longest sides. The notches are of the same size as those on the easel body. The notches interlock the top crossbar to the easel body. Tension is created between the top edge of the canvas or display and the interlocked top crossbar. The top crossbar securely holds the canvas or display from the top and also holds the easel body in place. The front lower edges of the easel body have curved supports, referred to as legs. The legs form a base that holds the bottom of a canvas or display. The third piece to the easel is the bottom crossbar, which spans across the front opening of the easel body. The bottom crossbar is an optional piece that can be used to raise the height of a canvas. The bottom crossbar has six inward notches on one edge that interlock with the bottom notches on the easel body. The bottom edge of the display or canvas is place on the bottom crossbar and secured in place by the top crossbar. 
     The easel has the following characteristics while in use: Folding the easel body down the centerline of weakness creates tension on both side panels causing pressure to reopen. The top crossbar holds the easel body securely in place by interlocking with the easel body. 
     There are preferably at least seven height settings for the top crossbar. These settings are based on the height of the canvas or display and are of the following dimensions, 11″, 12″, 14″, 16″, 18″, 20″, and 24″. There are four notches on the top crossbar to account for a change in the easel-opening angle due to different object heights. The two widest notches on the top crossbar are preferably for object heights from 11″ to 16″. The two inner notches are preferably for object heights of 18″ to 24″ in height. 
     A canvas or display rests securely on the legs and front panel edges of the easel body. The canvas or display is held at an incline, preferably between 50 and 70 degrees, against the front edges of the easel body. The weight of the object against the front panel edges rests rearwardly down the easel&#39;s adjoined side panels. Downward pressure from the object rests upon the legs of the easel body. The front of the easel body is spread open depending on the width of the object. The legs of the easel body are preferably within an inch from the lower corners of the object. Once the desired width is found, the top crossbar is placed against the top of the object, interlocking with the easel body. 
     The easel&#39;s “V” shaped base absorbs movement from the act of painting or drawing. Pressure is forced to the lower back point of the “V” to prevent excessive movement and retain stability of the easel and the load. 
     The bottom crossbar is similar to the top crossbar except that it preferably has six notches on one edge and interlocks generally with the lowest notches on the easel body. This bottom crossbar is used when an increase in the object&#39;s height is desired. The object rests on the bottom crossbar rather than the easel legs. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a flat plain view of the easel body. 
     FIG. 2 is a perspective side view of the easel body, in the upright position. 
     FIG. 3 is a plan view showing the top crossbar. 
     FIG. 4 is a plan view showing the bottom crossbar. 
     FIG. 5 is a perspective front operating view supporting a canvas or display with the top crossbar in place. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the most basic initial state the easel body comprises of a flat, isosceles triangle shape panel  1 . The panel  1  is preferably made of cardboard or flexible plastic. We prefer ¼″ double walled cardboard sheet  2 . The top of the panel  1  is curved around  3 . The bottom edge  6  has right angle corners, left  4  and right  5 , that extend up into an inward curve on each side, left  7  and right  8 , forming the legs of the easel body. There are seven notches on the left  9  and on the right  10  along the side edges of the panel  1 . A top crossbar  15  (FIGS. 2 and 3) interlocks with one notch on each side of panel  1  depending on the size of the display or canvas. The notches  9 ,  10  are the same width of the top crossbar&#39;s notches  17 ,  18 . There are two lower notches  13  on panel  1 . These notches  13  interlock with a bottom crossbar  22  (FIG. 4) when it is used. There is a line of weakness  11  along the center of panel  1 . Panel  1  is folded along the line of weakness  11  allowing the easel body to stand in an upright position  12 . The base of the easel body is folded to at least a one hundred-degree angle  14 . The top crossbar  15  preferably  15  and bottom crossbar  22  are made of the same material as the easel body. The top crossbar  15  has four inward angled notches  16 ,  17  along one edge. The top crossbar connects with the easel body by interlocking the notches on the left  9  and right  10  sides. The bottom crossbar  22  of the easel body preferably has three notches on each side of one edge  23 ,  24 . When in use, these notches interlock with the lower notches  13  on the easel body. The length of the bottom crossbar  22  is preferably longer than the top crossbar  15  and, each spans the front width of the easel when in the upright position. The legs  7 ,  8  hold the bottom of a canvas or display  20 . The top crossbar  15  secures the top of the canvas or display to form a complete and working painting or display easel. 
     This foregoing disclosure relates only to the preferred embodiments of the invention; it is intended to cover all changes and modifications of multiple purpose easels described which do not constitute departures from the spirit and scope of the invention as set forth in the appended claims.