Abstract:
A flag with a cam is pivotally attached to a sheet stock edge guide in a sheet loading tray of a copier or printer such that in the event the tray is overfilled, the edge of the sheet stack moves the cam to a position causing the flag to be raised to alert the user of the overfill.

Description:
BACKGROUND 
       [0001]    The present disclosure relates to sheet feeders for copying and printing machines of the type typically employed in offices and for photocopying documents. Such machines are commonly provided with a user loadable tray for insertion of sheets of the desired size into a feeding mechanism which advances the sheets into the photocopying machine. Trays of this sort intended for loading of at least 50 sheets of paper are provided with adjustable guides on the sides of the tray for maintaining the sheets in accurate registration and position for entry into the feeder. However, if the user overloads the tray the sheets can ride up over the guides and become skewed and enter the feeder in a disoriented manner which can result in improper feeding and jamming. Additionally, it has been found that damage to the sheet sensors in the feeding mechanism can result when jamming occurs. Furthermore, if excessive overload of the tray is experienced, the sheets can become driven into the nudger rolls resulting in damage to the rolls themselves. 
         [0002]    Heretofore, attempts to prevent tray overload have been addressed by incorporating a wiper blade for removal of excess paper above a specific height in the tray. If sufficient overload of the tray is encountered, the wiper blade can cause curling of a large number of sheets, which may result in forces applied to the tray components and guides; and, in such situations, failures of these components has been experienced. 
         [0003]    It has therefore been desired to provide a way or means of preventing or indicating to the user that the sheet stacker or tray has been overfilled and jamming or damage to the machine may occur. It has further been desired to provide such an indication to the user in a manner which is simple and low in cost to incorporate into existing machines, without adding additional complexity to the loading tray or machine. 
       SUMMARY 
       [0004]    The present disclosure describes a way of indicating to the user that a sheet stacker or tray for a copying machine is overfilled to the point that jamming or damage can occur. The present disclosure describes a rotatable flag pivotally mounted on the sheet edge guides employed in the tray whereby the flag remains in the upright position warning the user of overfill in the event that the sheets are loaded into the stacker or tray above a predetermined level. The flag of the present disclosure may be added to an existing sheet tray edge guide without significant modification of the basic components of the tray and edge guides. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a perspective view of a portion of a sheet stacker or tray showing an adjustable edge guide with the overfill indicating flag of the present disclosure mounted thereon. 
           [0006]      FIG. 2  is a perspective view of the pivotal flag component of the present disclosure; 
           [0007]      FIG. 3  is a perspective view of the flag of  FIG. 2  mounted on a retainer; 
           [0008]      FIG. 4  is a rear view of the retainer assembly of  FIG. 3  mounted on the edge guide of the tray of  FIG. 1 ; 
           [0009]      FIG. 5  is an edge view of the flag of the present disclosure in the upright or indicating position in solid outline and the retracted position shown in dashed line; 
           [0010]      FIG. 6  is a perspective view of an existing sheet stacker or tray with the elevate plate in place; and, 
           [0011]      FIG. 7  is a view similar to  FIG. 6 , with the elevate plate removed. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Referring to  FIGS. 6 and 7 , an example of a prior art sheet stacker or tray assembly is indicated generally at  100 , and includes front and rear triple towered sheet edge guides  102 ,  104  respectively and an adjustable side or length edge guide  106  adjustably mounted on the deck  108  of the assembly  100 . The sheet stack (not shown) when loaded into tray  10  registers against the side rail  110  of the tray. 
         [0013]    Edge guides  102 ,  104 , each have a leg portion or extension  112 ,  114  respectively with a toothed rack  116 ,  118  respectively along one side of the leg portion  112 ,  114 . The teeth of the racks  116 ,  118  engage respectively opposite sides of stationary toothed pinions  120 ,  122  to provide equal and oppositely directed movement of the edge guide upon user adjustment, for effecting centering of the sheet stack in the tray. 
         [0014]    It will be noted that the center tower of edge guide  104  has the inscription “MAX” thereon above a visible fill limit line for indicating to the user the level above which the tray should not be filled. 
         [0015]    Referring to  FIG. 1 , a portion of a stacker or a sheet loading tray for a copy or printing machine in accordance with the present disclosure is indicated generally at  10  and has a rear edge guide with towers  12 ,  14 ,  16  attached to a bar or strap  18  which has a leg or portion  20  thereof extending generally at right angles thereto which may be formed integrally therewith and which is slidably received on the base or bottom  24  of the tray. Guide surfaces  17 ,  21  are provided on the end of strap  18 -T for engaging corresponding guide surfaces (not shown) on base  24 . The leg portion  20  may include a notched rack  26  for engagement by a toothed pin (not shown) similar to pinions  120 ,  122  of  FIG. 7  for securing the guides  12 ,  14 ,  16  in a desired position for the selected print media sheets in a manner well known in the design of sheet trays. 
         [0016]    The center edge guide tower  14  has provided thereon an overfill indicator indicated generally at  28  provided thereon for providing visual indication to the user that the tray has been filled above the safe limit level as will hereinafter be described. 
         [0017]    Referring to  FIG. 2 , the indicator  28  comprises the tab or flag  30  which has a pair of oppositely extending half axles or trunnions  32 ,  34  formed thereon with a cam  36  extending from trunnion  32  and oriented to be aligned with the flag  30  and extend from the opposite side of the trunnion  32 . 
         [0018]    Referring to  FIG. 3 , the indicator  28  is shown with the trunnions  32 ,  34  received in a retainer  38  and snap locked therein for pivotal movement with respect thereto. The retainer  38  has a slot or notch  40  to provide clearance for cam  36  to rotate with the flag  30 . Retainer  38  may be provided with a pair of mounting towers  42 ,  44  each centrally apertured as denoted respectively by reference numerals  50 ,  52  for receiving suitable fasteners therethrough. 
         [0019]    Referring to  FIG. 4 , the retainer  38  is shown as positioned on the back side of edge guide  14  with the towers  42 ,  44  positioned for receiving mounting screws (not shown) therethrough for attachment to the edge guide  14 . The flag  30  is shown in  FIG. 4  in the retracted or horizontal position. 
         [0020]    Referring to  FIG. 5 , the tray assembly  10  is shown in edge view with the indicator  28  shown in solid outline with the flag  30  disposed vertically upward to provide an indication to the user that the tray has been filled to the limit. In the position shown in solid outline, the indicator  28  has cam  36  held in a downward position by the edge  56  of the sheet stack which has its top surface denoted by reference numeral  54 . If the top surface of the sheet stack  54  is below the position of cam  36  shown in solid outline in  FIG. 5 , the cam  36  will not be held in the downward position; and, the indicator, under the force of gravity, will rotate counterclockwise to the position shown in dashed outline thereby retracting the flag  30  and raising the cam  36  to the horizontal position shown in dashed outline. 
         [0021]    Thus, the present disclosure describes a unique and novel indicator assembly which may be attached to the edge guide of a media sheet tray or stacker for providing a visual indicator or flag which is raised upon the user loading the tray above the fill limit. 
         [0022]    It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.