Abstract:
A case feeder mechanism, used in quantities of two or more in a horizontal magazine, feeds cases to a removal position at the discharge end of the magazine, for extracting and processing by a case erecting machine. Each mechanism has two U-shaped channels, a sliding ratchet pawl channel and a fixed ratchet pawl channel, each containing a row of ratchet pawls. Each sliding ratchet pawl channel pushes the ratchet pawls against the back of the case group, driving the group towards the removal position. Individual sensing valves determine when the lead case is in the removal position and control each sliding ratchet pawl channel independently. Each fixed ratchet pawl channel holds the ratchet pawls in position, supporting the case group during resetting of the sliding ratchet pawl channel. To reload, cases are simply inserted, preferably in bundles, behind the existing case group.

Description:
BACKGROUND OF INVENTION  
       [0001]     This invention relates generally to packaging machinery such as machinery for squaring or erecting cases, and more specifically to horizontal magazines or hoppers for feeding packaging blanks.  
         [0002]     Packaging machines, case erectors in particular, often utilize horizontal magazines, which store a reserve or group of flattened cases. As the lead case of the group is removed into the machine for processing, the magazine&#39;s feeder apparatus moves the group of cases towards the removal position. This places the new lead case in position for removal. The feeder apparatus typically consists of a single plate, or other substantial structure, which is in contact with and applying pressure against the rearmost case of the group. These magazines tend to fall into two basic types, related to their reserve capacity.  
         [0003]     The first type of magazine is typically referred to as the “standard equipment” magazine, which has a capacity of approximately one hundred cases. This magazine is usually a basic, low—cost unit powered by a stored energy type of drive, such as gravity or spring tension. This type of magazine is typically inclined, so that the cases tend to flow downhill. A crude temporary support means is provided to facilitate reloading.  
         [0004]     The second type of magazine is typically referred to as the “extended capacity” magazine, capable of handling two hundred cases or more. This magazine is usually a costly and complex upgrade, powered by electricity, compressed air, or fluid power, and may also incorporate automated controls to simplify operation and reloading. This invention relates to embodiments of the first type of magazine, to which there are currently several disadvantages, such as those listed below.  
         [0005]     Retracting the feeding apparatus is a manual operation, typically involving reaching over the magazine and applying considerable effort. This is strenuous and awkward for the operator. Additionally, retracting the feeding apparatus can disturb or upset the remaining cases in the magazine, causing them to slide out of the magazine and disrupt operation of the case erecting machine.  
         [0006]     The temporary support means used to hold the group of cases while loading typically does not adequately feed the cases. This can cause erratic feeding and jamming of the case erecting machine while the magazine is being loaded.  
         [0007]     There are typically side guide rails provided to guide the outer edges of the cases. When loading, the additional cases must be lifted over these side guide rails from a position alongside the magazine, creating an awkward and difficult maneuver for the operator. When the magazine is mounted in an inclined manner, sloping downward towards the removal position, loading is made even more difficult.  
         [0008]     Most magazines must be adjustable to accommodate a wide range of case sizes. An attempt is made to size and position the feeder apparatus to accommodate the widely varying area of the flattened case. This leads to a compromise in the reliability of the feeder apparatus, relative to where a particular case size falls in the range of the magazine. The largest cases are often most poorly served.  
         [0009]     Most designs use only a single driving and/or braking mechanism to control case feeding. The lead case position is sensed or detected at only one point (the center of the bottom edge typically), if it is at all. This permits a good deal of variance in the attitude of the lead case as it is driven into the removal position. It may sit skewed, at an angle from top to bottom, or side to side, or both.  
         [0010]     As the magazine empties, the decreasing pressure on the lead case causes an inconsistency in the final stopped location, at the removal position of the magazine. Particularly in case erecting machines that use a rotary motion to remove and square-up the case, this affects the squareness of the delivered case.  
         [0000]     Objects And Advantages  
         [0011]     The primary object of this invention is to provide an improved mechanism for feeding cases into a case erecting machine.  
         [0012]     Another object of this invention is to provide a case feeder mechanism that functions well when mounted on a horizontally-positioned magazine.  
         [0013]     Another object of this invention is to provide a case feeder mechanism that allows the magazine to be easily loaded from the rear, in the direction the cases flow through the magazine.  
         [0014]     Another object of this invention is to provide a case feeder mechanism that allows the magazine to be loaded simply by inserting additional cases, without moving or otherwise affecting the feeding apparatus.  
         [0015]     Another object of this invention is to provide a case feeder mechanism that delivers cases from the smallest size to the largest with the same accuracy and consistency.  
         [0016]     Another object of this invention is to provide a case feeder mechanism that senses the position of the lead case in several areas across the face, and independently applies pressure behind these areas accordingly.  
         [0017]     A still further object of this invention is to provide a case feeder mechanism that is modular in design, allowing it to accommodate different magazine size ranges and designs.  
         [0018]     Yet another object of this invention is to provide an effective, low cost alternative to the standard equipment case feeder mechanisms, offered by most case erector manufacturers, that embodies many of the features of the case feeder mechanisms used on more expensive extended capacity magazines.  
         [0019]     Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.  
       SUMMARY OF THE INVENTION  
       [0020]     In accordance with the present invention, a case feeder mechanism, two or more of which are mounted within a case magazine, utilizes both fixed and movable means to alternately hold cases in, and ratchet cases into the delivery position of the case magazine. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0021]     The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.  
         [0022]      FIGS. 1, 1A ,  2 , and  2 A are perspective views of the case feeder mechanism from two different angles and in two different states of operation.  
         [0023]      FIG. 3  is a plan view of four case feeder mechanisms containing and feeding a group of cases.  
         [0024]      FIG. 3A  is an enlarged view of a portion of  FIG. 3 .  
         [0025]      FIGS. 4 and 4 A are perspective views of three case feeder mechanisms containing and feeding a group of cases.  
         [0026]      FIGS. 5 and 5 A are perspective views of four case feeder mechanisms containing and feeding a group of cases.  
         [0027]      FIG. 6  is a pneumatic schematic of the case feeder mechanism controls. 
     
    
     DETAILED DESCRIPTION  
       [0028]     Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.  
         [0029]     A preferred embodiment of a case feeder mechanism  100  is shown in  FIGS. 1 through 2 A.  FIGS. 1 and 2  show opposite perspective views of the mechanism  100  in the fed-forward position, and  FIGS. 1A and 2A  show opposite perspective views of the mechanism  100  in the reset position.  
         [0030]     The mechanism  100  includes various components which are well known to one of skill in the art. For example, the pneumatic cylinder  122  typically comprises a stationary cylinder body having a port at each end of its ends. The cylinder body clevis  124  is an integral part of the body of the cylinder and represents the mounting point by which the stationary cylinder body is attached. A movable rod passes longitudinally through the end seals of the body and a piston is fixed to the rod within the body. The cylinder rod clevis  126  is fastened to the rod of the cylinder and represents the mounting point by which the movable cylinder rod is attached. The piston has opposing surfaces which are acted upon by compressed air applied through the ports in the body. Depending on the differential of the pneumatic pressure applied to the ports, the piston is forced to slide within the body in a selected direction. The surface of the piston to which the rod is attached has a lesser amount of effective area which can be acted upon by the compressed air. Thus, if equal pneumatic pressures are applied to both ports, the piston will be forced towards the rod end of the cylinder. The degree of force thus applied to the piston is a fraction of that which would be exerted if only one port were to have the same pressure applied.  
         [0031]     Valves are utilized, which are also well known to one of skill in the art. Such valves are pneumatic or air pressure control valves which direct or divert the flow of compressed air. These valves, which typically have two operating positions, are actuated or triggered either by physical contact with a moving mechanical component, or by application of compressed air to a particular port of the valve. Examples of such valves would be the case travel limit valve  118 , the feeder direction valve  130 , the reload valve  144 , the flow control valve  142 , and the shuttle valve  140 , which are explained further in the following description.  
         [0032]     Linear bearings are utilized, which are also well known to one of skill in the art. Such linear bearings consist of a fixed linear bearing rail  112  and one or more movable bearings or load carriers  108 , which are mechanically interlocked with the rail  112 . The bearings  108  can travel along the rail  112  carrying their load to and fro, while being maintained in a precise physical relationship with the rail  112 .  
         [0033]     As shown in  FIG. 1 , two bearings  108  are attached to a fixed ratchet pawl channel  114 , and the rail  112  is attached to a sliding ratchet pawl channel  110  Channels  114  and  110  might be formed by bending sheet steel into a “U” shape. The sliding channel  110  can travel to and fro parallel to the fixed channel  114 , in the direction illustrated by arrows A and B in  FIGS. 1 through 2 A.  
         [0034]     As shown in  FIGS. 1 and 1 A, the fixed channel  114  and the sliding channel  110  each contain or carry an array of longitudinally spaced apart ratchet pawls  106 , arranged in rows within the channels  114  and  110 . The pawls  106  might be manufactured by injecting molten plastic into a mold designed to create the illustrated shape. The pawls  106  are rotatably attached to the channels  114  and  110  by ratchet pawl pivot pins  116 , which pass through a hole in the narrow end of each pawl  106 . The pawls  106  are able to pivot into and out of the channels  14  and  110  about the axis of the pins  116 . Ratchet pawl springs  104  are attached to the interior vertical surfaces of each of the pawls  106 , and are compressed between the interior vertical surface of the channels  114  and  110  and the pawls  106 . The springs  104  urge the pawls  106  into a position extending from the channels  114  and  110 . The lobe or tang on the end of each pawl  106 , opposite the end with the hole for the pin  116 , rests on the adjacent pawl  106 , limiting the outward travel of each pawl  106 .  
         [0035]     An example of the two working positions of the pawls  106  is shown in  FIG. 3A . The pawls  106  shown in the lower position are being extended from the sliding channel  110  and the fixed channel  114  by the springs  104  (shown in  FIG. 1 ). These pawls  106  have the lobes or tangs resting against the lower ends of the pawls  106  shown in the upper position. These pawls  106  are in contact with the back of the case group  138 . The pawls  106  shown in the upper position are being held inside the sliding channel  110  and the fixed channel  114  by the case group  138 .  
         [0036]     As shown in FIGS.  1 through  2 A, the valve  118  is attached to the top surface of the fixed channel  114  at the case delivery end of the mechanism  100 . A valve arm  120  is attached to the valve  118 . As the lead case  136  moves into the delivery position, the arm  120  is contacted and rotated, actuating the valve  118 . Thus, the valve  118  senses the presence of the lead case  136 , the delivery or arrival position. A case retaining brush  102 , which entraps and retains the lead case  136 , is attached to the bottom surface of channel  114 , at the case delivery end of the mechanism  100 .  
         [0037]     As shown in  FIGS. 2 and 2 A, a cylinder mounting bracket  121  is fastened to the channel  114 , and a cylinder rod connecting bracket  123  is fastened to the channel  110 . The cylinder  122  is attached via a clevis  124  to the cylinder mounting bracket  121 , and via a clevis  126  to the cylinder rod connecting bracket  123 . The valve  130  is attached to the exterior vertical surface of channel  114 . A reset mode valve tripper  128 , and a feed mode valve tripper  132  are attached to the exterior vertical surface of channel  110 .  
         [0038]     The mechanism  100  is designed such that the points of attachment are on the side or top exterior surfaces of the channel  114 , which must remain stationary as the mechanism  100  operates. Two to four mechanisms  100  would typically be attached to an adjustable horizontal magazine of known construction (not shown in the drawings). The attachment might be by bolts or weldments to various adjustment mechanisms, which are well known to one of skill in the art, in a manner that allows for vertical and/or horizontal adjustment.  
         [0039]     Two examples of possible applications for the mechanism  100  are illustrated by  FIGS. 4 through 5 A. In the first example shown in  FIGS. 4 and 4 A, three mechanisms  100  are shown held in position by an adjustable horizontal magazine of known construction, (not shown in the drawings). Surrounded by the three case feeder mechanisms  100  is the blank or case group  138 . The lead case  136  of the group  138  has been driven into position for removal. The vertical face of the lead case  136  is pressed against the suction cups  134 , which are part of a case erecting machine of known construction (not shown in the drawings). The cups  134  grasp and remove the lead case  136  from the magazine into the erecting machine for processing.  FIGS. 5 and 5 A show a similar possible configuration utilizing four mechanisms  100 . Each mechanism  100  operates independently to control the delivery position of an area or zone of the lead case  136 .  
         [0040]      FIG. 6  is a pneumatic schematic of the box feeder mechanism controls, wherein each of the valves mentioned earlier is illustrated. The control system is fed by and operates from compressed air delivered at a pressure of  90  psi, or pounds-per-square-inch, sources of which are very common to industrial environments. Plastic tubing and related fittings, well known to one of skill in the art, are used to connect the pneumatic components.  
         [0041]     The reload valve  144  is a mechanically actuated, spring returned valve. The valve  144  is shown held in the initial or at-rest position by spring pressure, wherein air flow is allowed from the inlet port to the first outlet port, and the second outlet port is open to atmosphere. The valve  144  changes positions as the pushbutton  143  is manually depressed against spring pressure. In the actuated position, the valve  144  allows air flow from the inlet port to the second outlet port, and the first outlet port is open to atmosphere. As the pushbutton  143  is released, spring pressure returns the valve  144  to the at-rest position.  
         [0042]     The feeder direction valve  130  is a mechanically actuated valve which utilizes a detent mechanism to hold the current position. The valve  130  changes to the feed position as the pushbutton  130 A is depressed, and to the reset position as the pushbutton  130 B is depressed. The valve  130  is shown in the feed position, wherein air flow is allowed from the inlet port to the first outlet port, and the second outlet port is open to atmosphere. In the reset position, the valve  130  allows air flow from the inlet port to the second outlet port, and the first outlet port is open to atmosphere.  
         [0043]     The case travel limit valve  118  is a mechanically actuated, spring returned valve. The valve  118  changes positions as the valve arm  120  is rotated against spring pressure. The valve  118  is shown in the actuated position, allowing air flow from the inlet port to the outlet port. As the arm  120  is released, spring pressure returns the valve  118  to the at-rest position, wherein the inlet port is blocked, and the outlet port is open to atmosphere.  
         [0044]     The shuttle valve  140  is actuated by air pressure to either or both of the two inlet ports. The valve  140  allows air flow from the inlet port having the highest positive pressure to the outlet port, while blocking the remaining inlet port. In this particular application, two valves  140  are connected in series, the output of the first valve  140  having been connected to an input port of the second valve  140 . The net result of this configuration is that the highest of three possible sources of air pressure is allowed to flow to the outlet port of the second valve  140 .  
         [0045]     The flow control valve  142  consists of a combination of a check valve and a needle valve, connected parallel to each other. The check valve allows full air flow in one direction, and no air flow in the opposite direction, while the needle valve allows adjustably restricted air flow in either direction. The net result of this configuration is that the valve  142  allows full air flow in one direction, and adjustably restricted air flow in the opposite direction. The valve  142  is typically used to control the operating speed of an air cylinder, such as cylinder  122 , by allowing full compressed air flow into a port, and adjustably restricted exhaust air flow out of the same port.  
         [0046]     All of the components shown in  FIG. 6  are mounted upon each mechanism  100 , with the exception of the reload valve  144 . The reload valve  144  is mounted on the magazine, within reach of a loading operator standing in position to load the magazine. Only one reload valve  144  is required per magazine, and controls all of the mechanisms  100  mounted upon the magazine. The reload valve  144  has attached to the outlet ports several of a connector  145 A, and a connector  146 A. Each mechanism  100  has a connector  146 B attached to an inlet port of one of the shuttle valves  140 , and a connector  145 B attached to the inlet port of the feeder direction valve  130 . As many mechanisms  100  as are required are connected to the reload valve  144 , via connectors  145 A through  146 B.  
         [0047]     Each of the mechanisms  100  shown in  FIGS. 4 through 5 A is illustrated in the at-rest condition. Each mechanism  100  operates independently of the others, in the manner described by the following.  
         [0048]     The reload valve  144  is in the at-rest position, allowing compressed air flow to the inlet port of the feeder direction valve  130 . The feeder direction valve  130  is in the feed position, allowing compressed air flow to the cylinder port  122 B and the inlet port of the case travel limit valve  118 . The case travel limit valve  118  is being held in the activated state via the valve arm  120 , which is in contact with the current lead case  136  The case travel limit valve  118  allows compressed air flow to the shuttle valves  140  which, in turn, allow compressed air flow to the cylinder port  122 A of the air cylinder  122 . As a result, both ports  122 A and  122 B of the cylinder  122  are pressurized to  90  psi. As described earlier, this results in a reduced degree of force being applied to the piston of the cylinder  122  in the direction of the rod end. This in turn applies force to the sliding channel  110 , and the attached row of pawls  106 , in the feed direction. Thus, the position of the case group  138  is maintained by the ratchet pawl  106  within the sliding channel  110  that is currently in contact with and pressed against the rearmost case of the case group  138  This, in turn, keeps the adjacent area of the current lead case  136  in position for removal. The adjacent area of the current lead case  136  is held inside the magazine by case retaining brush  102 , assisted by the valve arm  120 .  
         [0049]     As the suction cups  134  remove the current lead case  136  into the case erecting machine for processing, the valve arm  120  swings away from the case group  138  and clear of the lead case  136 . The case retaining brush  102  holds back the adjacent area of the remaining case group  138 . The valve arm  120  then retracts back against the new lead case  136 , returning the case travel limit valve  118  to the at-rest position. The case travel limit valve  118  allows exhaust air flow from the cylinder port  122 A to atmosphere. As  90  psi applied to the cylinder port  122 B, the air cylinder  122  applies maximum force to the sliding channel  110 , which is driven towards the discharge end of the magazine as illustrated by arrows A, B, and C. This in turn drives the ratchet pawl  106  that is currently in contact with the back side of case group  138  against the group, moving or ratcheting the adjacent area of the new lead case  136  into position for removal. The case travel limit valve  118  is actuated via the valve arm  120  by the new lead case  136 . This again allows compressed air flow to the cylinder port  122 A of the air cylinder  122 . The mechanism  100  is again in an at-rest condition, awaiting the removal of the current lead case  136   
         [0050]     As the sliding channel  110  moves, the amount of one case thickness at a time, towards the discharge end of the magazine, the air cylinder  122  approaches the fully extended position, illustrated in  FIGS. 2 and 4 . This initiates the resetting process of the case feeder mechanism  100 . The pawl  106 , contained in the fixed channel  114 , that is nearest the rearmost case of the case group  138  is cleared by the group and returned to the extended position. This particular pawl  106  moves from the position illustrated by the upper pawl  106  show in  FIG. 3A , to the position illustrated by the lower pawl  106 This pawl  106 will support, and hold the position of, the adjacent area of the case group  138  during the resetting process.  
         [0051]     The reset mode valve tripper  128  reaches and actuates the feeder direction valve  130 , which is then shifted to the reset position, as shown in  FIG. 6 . The feeder direction valve  130  allows exhaust air flow from the cylinder port  122 B to atmosphere, and compressed air flow to the cylinder port  122 A, via the shuttle valves  140  The cylinder  122  then fully retracts, moving the sliding channel  110  to the reset position, illustrated in FIGS.  1 and  2 . Simultaneously, the ratchet pawl  106 , contained in the sliding channel  110 , that is immediately nearest the rearmost case of the case group  138  is moved clear of the group and returned to the extended position. This particular ratchet pawl  106  moves from the position illustrated by the upper pawl  106  show in  FIG. 3A , to the position illustrated by the lower pawl  106 . This particular pawl  106  will resume driving the case group  138  after the resetting process is completed.  
         [0052]     As the air cylinder  122  reaches the fully retracted position, the feed mode valve tripper  132  reaches and actuates the feeder direction valve  130 , which is then shifted back to the feed position, as shown in  FIG. 6 . The case feeder mechanism  100  can now resume the process of feeding boxes, as described above.  
         [0053]     As the case group  138  becomes depleted, reloading becomes necessary. Groups of flattened cases, preferably strapped into bundles, are inserted into the area surrounded by the three case feeder mechanisms  100 , in the direction of the arrows C, as shown in  FIGS. 4 through 5 A. The loading operator pushes the fresh group of cases in the feed direction until the cases are near the back of the case group  138  The loading operator then depresses the pushbutton  143  of the reload valve  144 . The reload valve  144  allows compressed air flow to the inlet ports of the shuttle valves  140  of all of the mechanisms  100  simultaneously, which, in turn, allow compressed air flow to the cylinder ports  122 A of the air cylinders  122 . The reload valve  144  also allows exhaust air flow from the inlet ports of the feeder direction valves  130 . The cylinders  122  then fully retract, simultaneously resetting all of the mechanisms  100 , in the manner described earlier. When all of the mechanisms  100  are reset, the operator then releases the pushbutton  143  of the reload valve  144 , allowing the mechanisms  100  to return to the feed mode of operation. As the mechanisms  100  resume cycling, the additional group of cases is then driven into the case group  138 , marrying the two groups together into the new case group  138 .  
         [0054]     While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.