Patent Publication Number: US-9422130-B1

Title: Pivoted belt clamp to align with belt twist during linear motion in print job finisher

Description:
BACKGROUND 
     Disclosed herein are systems that improve the operation of print job finisher machines. 
     Embodiments of the disclosure are well suited for the paper stack alignment portion of a print job finisher machine. 
     SUMMARY 
     Some printing/copying systems include a finisher that performs one or more finishing operations such as, for example, stapling or other binding. Some of these finishers have an alignment function that aligns a stack of sheets of media before stapling or other binding. Alignment mechanisms can use one or more tampers to tamp the stack into alignment. Such a tamper can be attached to a belt that reciprocates to bring the tamper into contact with the stack. The tamper can also be slidingly attached by way of bushings to a stationary rod such that movement of the tamper is constrained to a linear movement as the belt moves a tamper body to which the tamper is attached. The belt can twist as a result of the forces acting on the belt during the tamping operation. If the tamper is rigidly fixed to the belt, then the twisting of the belt can cause binding between the bushings and the rod. 
     Embodiments of the disclosure provide an improved connection between the tamper and the belt that lessens or eliminates binding between the bushings and the stationary rod. 
     An embodiment of the disclosure may include a sheet stack aligning mechanism for a print job finishing machine. The mechanism can include a first belt driven in a reciprocating motion in a first direction and a second direction opposite to the first direction; a first stationary rod having a longitudinal direction and configured to be stationary relative to a body of the print job finishing machine; a first sheet stack alignment tamper that is configured to tamp a stack of sheets of media into alignment; and a first belt clamp. The first belt clamp has a first main body attached to the first sheet stack alignment tamper, a first pivot pin, a first belt attachment portion pivotably attached to the first main body by the first pivot pin, the first belt attachment portion being fixed to the first belt such that the first belt attachment portion does not move relative to the first belt, and a first bushing portion fixed to the first main body and slidably attached to the stationary rod. The first pivot pin permits the first belt attachment portion to follow a movement of the first belt in a direction non-parallel to the longitudinal direction of the stationary rod while the first main body of the first belt clamp moves only in the longitudinal direction of the stationary rod. 
     Another embodiment of the disclosure may include a print job finishing machine. The machine can include a body; a paper stacking area for holding a stack of sheets of media inside the body; and a sheet stack aligning mechanism inside the body. The mechanism has a first belt driven in a reciprocating motion in a first direction and a second direction opposite to the first direction; a first stationary rod having a longitudinal direction and being stationary relative to the body of the print job finishing machine; a first sheet stack alignment tamper that is configured to tamp the stack of sheets of media into alignment; and a first belt clamp. The first belt clamp has a first main body attached to the first sheet stack alignment tamper, a first pivot pin, a first belt attachment portion pivotably attached to the first main body by the first pivot pin, the first belt attachment portion being fixed to the first belt such that the first belt attachment portion does not move relative to the first belt, and a first bushing portion fixed to the first main body and slidably attached to the stationary rod. The first pivot pin permits the first belt attachment portion to follow a movement of the first belt in a direction non-parallel to the longitudinal direction of the stationary rod while the first main body of the first belt clamp moves only in the longitudinal direction of the stationary rod. 
     Some embodiments also include a second belt driven in a reciprocating motion in the first direction and the second direction; a second sheet stack alignment tamper that is configured to tamp the stack of sheets of media into alignment; and a second belt clamp. The second belt clamp has a second main body attached to the second sheet stack alignment tamper, a second pivot pin, a second belt attachment portion pivotably attached to the second main body by the second pivot pin, the second belt attachment portion being fixed to the second belt such that the second belt attachment portion does not move relative to the second belt, and a second bushing portion fixed to the second main body and slidably attached to the stationary rod. The second pivot pin permits the second belt attachment portion to follow a movement of the second belt in a direction non-parallel to the longitudinal direction of the stationary rod while the second main body of the second belt clamp moves only in the longitudinal direction of the stationary rod. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of finisher in accordance with embodiments of the disclosure; 
         FIG. 2  shows an example of a paper stack alignment portion of a finisher; 
         FIG. 3  shows an example of belt holder; 
         FIG. 4  shows an example of a belt holder in accordance with embodiments of the disclosure; 
         FIG. 5  shows an example of a belt holder in accordance with embodiments of the disclosure; 
         FIG. 6  shows an example of a belt holder in accordance with embodiments of the disclosure; 
         FIG. 7  shows an example of a paper stack alignment portion of a finisher in accordance with embodiments of the disclosure; 
         FIG. 8  shows an example of a belt holder in accordance with embodiments of the disclosure; and 
         FIG. 9  shows an example of a belt holder in accordance with embodiments of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosed embodiments may include a sheet stack aligning mechanism for a print job finishing machine. The mechanism can include a first belt driven in a reciprocating motion in a first direction and a second direction opposite to the first direction; a first stationary rod having a longitudinal direction and configured to be stationary relative to a body of the print job finishing machine; a first sheet stack alignment tamper that is configured to tamp a stack of sheets of media into alignment; and a first belt clamp. The first belt clamp has a first main body attached to the first sheet stack alignment tamper, a first pivot pin, a first belt attachment portion pivotably attached to the first main body by the first pivot pin, the first belt attachment portion being fixed to the first belt such that the first belt attachment portion does not move relative to the first belt, and a first bushing portion fixed to the first main body and slidably attached to the stationary rod. The first pivot pin permits the first belt attachment portion to follow a movement of the first belt in a direction non-parallel to the longitudinal direction of the stationary rod while the first main body of the first belt clamp moves only in the longitudinal direction of the stationary rod. 
     Some embodiments also provide a second belt driven in a reciprocating motion in the first direction and the second direction; a second sheet stack alignment tamper that is configured to tamp the stack of sheets of media into alignment; and a second belt clamp. The second belt clamp has a second main body attached to the second sheet stack alignment tamper, a second pivot pin, a second belt attachment portion pivotably attached to the second main body by the second pivot pin, the second belt attachment portion being fixed to the second belt such that the second belt attachment portion does not move relative to the second belt, and a second bushing portion fixed to the second main body and slidably attached to the stationary rod. The second pivot pin permits the second belt attachment portion to follow a movement of the second belt in a direction non-parallel to the longitudinal direction of the stationary rod while the second main body of the second belt clamp moves only in the longitudinal direction of the stationary rod. 
     Some printing/copying systems include a finisher that performs one or more finishing operations such as, for example, stapling or other binding. Some of these finishers have an alignment function that aligns a stack of sheets of media before stapling or other binding.  FIG. 1  shows a finishing machine or finisher  100  having a sheet stack aligning mechanism  200 , a body  110 , and a paper stacking area  120  for holding a stack of sheets of media inside the body  110 . Alignment mechanisms can use one or more tampers to tamp the stack into alignment. Such a tamper can be attached to a belt that reciprocates to bring the tamper into contact with the stack. The tamper can also be slidably attached by way of bushings to a stationary rod such that movement of the tamper is constrained to a linear movement as the belt moves a tamper body to which the tamper is attached. The belt can twist as a result of the forces acting on the belt during the tamping operation. If the tamper is rigidly fixed to the belt, then the twisting of the belt can cause binding between the bushings and the rod. 
       FIG. 2  shows an example of an alignment mechanism  200  that has two belt driven tampers that tamp a stack of sheets into alignment. A first one of the mechanisms (first sheet stack alignment tamper)  300  has a tamper that extends below the mechanism shown in  FIG. 2  and is attached to a carriage  330 . Carriage  330  is attached to a belt  310  that runs around a pulley  320 . As belt  300  is driven in a reciprocating motion, the tamper is pushed into contact (and removed from contact) with the stack of sheets. A second one of the mechanisms (second sheet stack alignment tamper)  400  has a tamper that extends below the mechanism shown in  FIG. 2  and is attached to a carriage  430 . Carriage  430  is attached to a belt  410  that runs around a pulley  420 . As belt  410  is driven in a reciprocating motion, the tamper is pushed into contact (and removed from contact) with the stack of sheets. As the stack of sheets is pressed between the two tampers, the sheets in the stack are brought into alignment with each other. While the example shown in  FIG. 2  has two tampers and associated mechanisms, other examples have only one tamper or more than two tampers. 
       FIG. 3  is a closer view of part of the mechanism  300 .  FIG. 3  shows that carriage  330  has two bushings  332  that are mounted to a stationary rod such that the bushings and carriage  330  can slide along the rod. Carriage  330  has a belt attachment portion  334  that securely holds belt  310  such that carriage  330  moves with any movement of belt  310 . 
     Embodiments of the disclosure recognize that belt  310  can twist during movement due to the forces exerted on belt  310 . This twisting is transferred to carriage  330  through belt attachment portion  334  and can exert forces on bushings  332  that can cause bushings  332  to bind on the stationary rod. These forces exerted on bushings  332  can result in increased frictional forces and increased noise. 
       FIG. 4  shows an example of an embodiment of the disclosure that reduces or prevents the transmission of the above described twisting forces to the bushing/rod interface. In  FIG. 4 , carriage  500  has a main body  520  that is fixed to, in this example, two bushings  510  that slid along the stationary rod. A belt attachment portion  530  securely holds belt  310  such that belt attachment portion  530  moves with any movement of belt  310 . However, belt attachment portion  530  is pivotably attached to main body  520  by a pivot pin  540  such that belt attachment portion  530  can pivot relative to main body  520  while still transferring transitory motion from belt  310  to main body  520 . This pivoting motion reduces or eliminates the binding forces that can exist in the example shown in  FIGS. 2 and 3 . 
       FIG. 5  shows carriage  500  removed from the alignment mechanism for clarity.  FIG. 5  shows belt attachment portion  530  in a pivoted upward position as opposed to the more parallel position shown in  FIG. 4 . Also shown in  FIG. 5  are protrusions  535  that assist in gripping belt  310 . 
       FIG. 6  shows a slightly different version of carriage  500 . In this example, belt attachment portion  530 ′ sits down inside of main body  520  when in the parallel position and has a shorter section that includes protrusions  535 ′. 
       FIG. 7  shows an alignment mechanism using two of the carriages shown in  FIG. 4 .  FIGS. 8 and 9  are closer views of the two carriages and their interactions with belts  310  and  410 . In  FIG. 8  carriage  500  has two bushings  510  that slidingly mount the main body  520  of carriage  500  to the stationary rod. The pivoting attachment of belt attachment portion  530  to main body  520  by pivot pin  540  is clearly shown. Also shown in  FIG. 8  is a spring that cushions the tamping action of that tamper that is actuated by main body  520 .  FIG. 9  shows that second carriage  600  has two bushings  610  that slidably mount the main body  620  of carriage  600  to the stationary rod. The pivoting attachment of belt attachment portion  630  to main body  620  by pivot pin  640  is clearly shown. In this example, both carriages are mounted to the same stationary rod. 
     It will be appreciated that variations 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.