Abstract:
A cut-off mechanism for severing a record member in a data terminal device is disclosed which includes a cutting wheel mounted on a pivoted support arm member which is so mounted that when rocked about its pivot by an actuating member such arm member moves the cutting wheel in a rectilinear plane along a guide member to cut across the record member. The support arm member is pivoted on a stud positioned within an arm member slot which allows the arm member to move in a vertical direction as the cutting wheel traverses the record member. Provisions are made to change the position of the pivot point of the arm member and the actuating member to vary the length of the cutting stroke of the cutting wheel allowing for partial cuts of the record member to be made.

Description:
FIELD OF THE INVENTION 
     This invention relates to cutting devices, and more particularly to a paper strip cutting wheel which includes a mechanism for driving the cutting wheel. 
     BACKGROUND OF THE INVENTION 
     In present day merchandising operations wherein electronic cash registers or data terminal devices are utilized to calculate the amount due and paid, a copy of the transaction in the form of a printed receipt is produced and given to the customer. Prior mechanisms which have been used for cutting the receipt include perforating a row of holes across the receipt or incorporating a knife member pivoted at one edge of the strip of receipt paper and actuated to cut across the strip, thereby severing the printed receipt from the strip. These mechanisms have been found to have inherent defects which detract against their use. In the case of perforating a line of holes across the receipt, large amounts of paper dust are created which tend to settle within the various mechanisms of the terminal device, thereby causing mis-operation of the mechanism. In the case of the pivoted knife mechanism, it has been found that the mechanism requires frequent adjustments to provide the proper shearing action of the blade so as to insure a good cut of the receipt strip. It is therefore an object of this invention to provide a paper strip cutting mechanism for use in a data terminal device which is positive in its cutting action and reliable in its operation. It is a further object of this invention to provide a paper strip cutting mechanism which is simple in its construction and therefore low in cost. 
     SUMMARY OF THE INVENTION 
     In order to carry out these objects, there is provided a cutting wheel rotatably supported on a knife arm slidably pivoted on a support stud. A cam member positioned within a slot in the knife arm is moved in a circular direction by a drive member thereby oscillating the knife arm about the stud. The stud is positioned within a second slot in the knife arm, such that as the knife arm is oscillated, the stud will ride in the second slot along the length of the knife arm in such a manner as to allow the knife arm to move in a generally vertical direction which moves the cutting wheel in a plane across the record member, thereby severing the record member. The cutting wheel is spring urged against a shearing surface as it moves along its cutting path to provide a positive cutting action. Sensing means are provided to control the operation of the drive member so that the knife arm will be oscillated through one cutting cycle. There is also provided a support guide member coacting with a spring urged roller member for supporting and guiding the cutting wheel along a predetermined cutting path, the support guide member including a wedge portion for stopping and holding the cutting wheel in its home position. 
     The foregoing and other objects, features and advantages of the invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a front elevational view of the cutting mechanism showing the knife arm in the home position and also in a position approaching the cutting movement. 
     FIG. 2 is a side elevational view of the cutting mechanism. 
     FIG. 3 is a sectional view taken on lines 3--3 of FIG. 1 showing on an enlarged scale details of the cutting wheel in its home position on the support guide. 
     FIG. 4 is a partial sectional view taken on line 4--4 of FIG. 2 showing details of the wedge portion of the support guide member. 
     FIG. 5 is a diagrammatic representation of the timing of the operation of the cutting mechanism. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, FIG. 1 shows a front view of the cutting mechanism of the present embodiment which can be mounted within a data terminal device. Included in the mechanism is a knife bracket 20 having an extension 21 (FIG. 2) projecting forwardly from the main body of the bracket and an overhang portion 22 extending outwardly from the top of the bracket forming a recessed area 23 within which is positioned a cutting wheel 24 (FIG. 2). The upper portion of the cutting wheel 24 projects through a slot 25 (FIG. 3) located in the top surface 29 of the overhang portion 22 and into a recessed area 26 of a plate 27 mounted on a pair of raised portions 28, 30 (FIG. 1) of the overhang 22 by some suitable fastening means such as rivets 31 or push-on clips (FIG. 3). As best seen in FIG. 1, the plate 27 forms a slot 32 with the top surface 29 of the overhang portion 22, through which slot a record member strip, being in the present case a strip of receipt paper, extends so as to be severed by the movement of the cutting wheel 24 during operation of the terminal device. 
     Secured to the rear side of the knife bracket 20 by any suitable means such as screws 18, 19 (FIG. 1), which are mounted in adjustment slots 16, 17, respectively, is a motor 33 (FIG. 2) whose drive shaft 34 extends through a further adjustment slot 29 to the front side of the bracket 20, and to which is secured a hub 35 (FIG. 2). As shown in FIG. 1, affixed to the hub 35 is a cam arm member 36 which supports on its end a stud 37. Operatively associated with the arm member 36 is a knife arm 38 which includes a longitudinal slot 40 within which is positioned the stud 37. As shown more clearly in FIG. 1, the knife arm 38 has a second longitudinal slot 41 within which is positioned a stud 42 removably mounted in one of three raised bosses 43, 43a and 43b located on the lower front side of the knife bracket 20. As understood from FIG. 1, upon operation of the motor 33, the arm member 36 will be rotated about the shaft 34 allowing the stud 37 to rock the knife arm 38 about the stud 42 while sliding along the slot 40 as shown in dotted lines in FIG. 1. It is obvious that the extent of rocking of the knife arm 38 by the motor 33 is determined by the location of the stud 41 in one of the bosses 43, 43a, 43b and the position of the motor shaft 34 within the adjustment slot 29. Thus, when the stud 42 is positioned in the boss 43 and the motor 33 is positioned in the left portion of the slot 29, as viewed in FIG. 1, the knife arm will be rotated through its longest arc by the motor 33 to provide a full cut of the receipt strip. On the other hand, mounting the stud 42 in either of the other two bosses 43a, 43b together with moving the motor to the right within adjustment slot 29 will provide for partial cuts of the receipt strip. 
     As best seen in FIGS. 2 and 3, the top portion of the knife arm 38 consists of a pair of yoke extensions 44, 45 between which is rotatably mounted a shaft 46. The shaft 46 is suitably mounted in the yoke extensions by means of clips 49 or the like which rotate with the shaft. Associated with the shaft 46 is the cutting wheel 24 rotatably and slidably mounted thereon and to which is secured a hub 47. As described previously, the cutting wheel 24 extends through the slot 25 in the top of the knife bracket overhang portion 22 into the recessed area 26 of the top plate 27. As shown in FIG. 3, the cutting wheel 24 is moved into engagement with a shear edge 48 of the recessed area 26 by the action of a compression spring 50 positioned on the hub 47 and mounted between the cutting wheel 24 and a guide roller 51 rotatably mounted on the shaft 46. 
     As best understood from FIGS. 3 and 4 inclusive, the roller 51 is positioned to ride on a horizontal surface 52 of a ledge or guide support 53 extending across the top of the knife bracket 20 and which supports the roller 51, cutting wheel 24 and the knife arm 38. The guide support 53 has a pair of depending arm members 54, 55 (FIG. 1), each having a bracket portion 56 containing a slot 57 which is slipped over some suitable support member such as a screw 58 or the like mounted in the knife bracket 20. This arrangement allows the guide support 53 to be adjusted in a vertical direction by positioning the brackets 56 on the screws 58 to level the guide support. 
     As best seen in FIGS. 3 and 4, the guide support 53 has a cam surface 60 which functions as a guide against which the roller 52 is urged by the action of the spring 50. Movement of the knife arm 38 results in the roller rolling on the surface 52 and along the cam surface 60 of the guide support guiding the cutting wheel 24 in a horizontal direction to transverse the receipt strip in a cutting movement. As seen in FIG. 4, the right hand portion of the cam surface 60 angles inwardly towards the rear of the knife bracket forming a wedge portion which moves the washer 51 against the spring 50 as the knife arm 38 moves into its home position. When this occurs the spring 50 will be further compressed, thus wedging the roller 51 against the cam surface 60 and the cutting wheel 24 against the shearing surface 48 of the top plate 27 so as to hold the arm in the home position. 
     The knife arm 38 has a right hand extension 61 (FIG. 1) which coacts with a photo-electric cell 62 (FIG. 2) mounted on a bracket 63 secured to the forward extension 21 of the bracket 20. A light source 64 (FIG. 2) is also mounted on the bracket 63 and operates in conjunction with the photo-electric cell 62 in a manner well known in the art to generate a control signal for use in controlling the operation of the motor 33 in accordance with the position of the knife arm 38 as will be described more fully hereinafter. 
     In the operation of the cutting mechanism in accordance with the invention, the data terminal device will have been operated to print data on the receipt strip positioned on the surface 29 of the knife bracket 20 and located within the slot 32 (FIG. 1). After the printing operation has occurred and the receipt strip moved to the proper position, the motor 33 will be energized to rotate the arm 36 and the knife arm 38 counter-clockwise as viewed in FIG. 1. Since the knife arm 38 is slidably mounted with respect to the stud 37 secured to the cam arm 36 and likewise slidably mounted on the pivot stud 42, rocking of the knife arm 38 will result in the knife arm simultaneously sliding in a downward direction on the pivot stud 42 due to the weight of the arm 38 together with the roller 51 and the cutting wheel 24. This downward movement of the arm 38 will allow the roller 51 to move along the surface 52 of the guide plate 53 in a horizontal direction. Due to the friction between the roller 51 and the cam surface 60 of the guide support caused by the action of the spring 50, movement of the arm 38 will result in the rotation of the roller 51 as it moves along the guide plate 53. In a similar manner, friction between the edge of the cutting wheel 24 and the shear edge 48 of the top plate 27, in addition to the friction between the cutting wheel and the receipt strip, will result in the rotation of the cutting wheel 24 in a clockwise direction as viewed in FIG. 1. This rotation of the cutting wheel will sever the receipt strip. 
     As the knife arm 38 is rocked back towards its home position, the roller 51 will be moved into the wedge portion of the guide plate 53 (FIG. 4) where the spring 50 will be compressed, thereby exerting a greater force on both the roller 51 and the cutting wheel 24. Movement of the knife arm 38 into its home position as shown in solid lines in FIG. 1 will result in the extension 61 of the knife arm 38 blocking the light from the light source 64 so that the signal from photo-electric cell 62 upon the blocking of the light will stop the operation of the motor 33. Since at this time the roller 51 and the cutting wheel 24 are in the wedged portion of the guide plate 53, the arm 38 will be held in its home position and thus prevented from coasting out of the home position. As stated previously, if a partial cut of the receipt strip is desired, the pivot stud 42 will be positioned in one of the other raised bosses 43a and 43b and the motor shaft 34 moved to the proper position in the adjustment slot 29 depending on the length of cut desired. 
     Referring now to FIG. 5, there is shown the timing of operation of the cutting mechanism. In the normal operation of the data terminal, the receipt strip will have been moved to a cutting position after the printing operation has occurred. When a Receipt Line Feed pulse generated within the data terminal is dropped (FIG. 5), a Knife Input pulse will be raised by the data terminal which pulse energizes the motor 33 -- thus initiating rocking of the knife arm 38 in the manner described previously. As the knife arm 38 leaves the home position, the extension 61 will move away from the photo-cell 62 allowing the photo-cell to receive the light from the light source 64, thereby allowing the Knife Home signal to go false (FIG. 5). This will occur within 110 milliseconds after the start of rocking of the knife arm 38. Upon the arm 38 returning to the home position, the extension 61 will block the light from the source 64 resulting in the Knife Home signal going true. Within 0.5 of a millisecond (FIG. 5) after the Knife Home signal has gone true, the Knife Input signal will be dropped and thus deenergize the motor. As shown in FIG. 5, for purposes of motor protection the Knife Input signal will not last more than 500 milliseconds. Also, should the knife arm 38 not return to its home position with 500 milliseconds of its initial operation, a time-out circuit of conventional design is used to interrupt the operation of the data terminal so that the cause of the knife arm not returning to its home position can be eliminated. 
     While the principles of the invention have now been made clear in an illustrated embodiment, it will be obvious to those skilled in the art that many modifications of structure, arrangements, elements and components can be made which are particularly adapted for specific environments and operating requirements without departing from these principles. As an example, while the cutting surface has been shown in the disclosed embodiment to be in a horizontal plane, it is obvious that if the cutting surface is positioned in a vertical direction, the arm 38 would be required to be biased by a spring for movement in a direction away from the cutting surface to function in the manner set out above. Or a second guide surface could be provided forming a slot with the guide surface 52 to contain the roller 51 during its vertical movement. The appended claims are therefore intended to cover any such modification, within the limits only of the true spirit and scope of the invention.