An apparatus for cutting record medium

Abstract: An apparatus for cutting record medium including a rotatable cutting member (82) mounted on support means (74) coupled to a carriage (52). The cutting member (82) engages with a fixed member (90) as the carriage (52) travels along a guide path. A positive drive includes a gear cluster (76,78,80) arrangement operated by a toothed belt (68) which is stretched across the apparatus. The cutting member (82) is maintained in engagement with the fixed member (90) by means of a torsion spring (98) tending to rotate the knife and its support means (74) in one direction.

Description: The present invention relates to an apparatus for cutting record medium and more particularly, but not exclusively, to an apparatus including a rotatable cutting member mounted on a carriage in a printer. In a dot matrix printer which is used for receipt, slip and journal printing operations, the receipt paper is cut after each receipt transaction and a receipt is given to the customer. The device for cutting the receipt paper has commonly been a tool, a blade or a cutter wheel. In one arrangement a carriage is provided with a round blade that is driven in the horizontal direction along a guide member. The round blade is journaled on a shaft supported to a bracket and the round blade is urged against a fixed blade by a spring on the shaft. A receipt is cut off by the round blade upon horizontal movement of the carriage. The round blade is rotated only by frictional force generated during a receipt cutting operation. If foreign material slows or stops the rotation of the blade, a smooth cutting operation is not possible, and uneven rotation of the blade causes wearing of such blade. Patent Abstract of Japan vol. 10 no. 70 (m-462) [2127] 19/03/86 and JP-A-60 214 982, discloses an arrangement in which a circular blade is driven to rotate during a paper cutting operation by way of a toothed belt which engages gear means connected to the blade. However, the engagement between the toothed belt and the gear means disadvantageously does not ensure a positive driving force to the gear means and blade. One object of the present invention is to overcome the above disadvantages so that the cutting operation is certain and smooth, even if foreign material is present in the cutting area. Accordingly, the present invention provides an apparatus for cutting a record medium including a rotatable cutting member rotatably mounted on support means movably mounted on a carriage, drive means for moving said carriage in a reciprocal manner along a guide path relative to frame means of the apparatus, said rotatable cutting member being operably associated with a fixed cutting member mounted on said frame means for cutting said record medium upon driving of said carriage along said guide path, gear means mounted on said support means and engageable with a resilient elongated toothed member mounted on said frame means for rotating said cutting member in response to movement of said carriage along said guide path, and roller means for urging said toothed member into engagement with said gear means, characterized in that said roller means include a pair of spaced rollers journaled on said support means and positioned in offset manner for urging said toothed member into engagement with said gear means. An embodiment of the present invention will now be described with reference to the accompanying drawings in which:- Fig. 1 is a perspective view of a dot matrix printer incorporating the subject matter of the present invention; Fig. 2 is a right side elevational view in diagrammatic form showing the arrangement of certain elements of the printer; Fig. 3 is a left side elevational view in diagrammatic form showing the arrangement of such certain elements of the printer; Fig. 4 is a perspective view, taken from the front and left side, of a portion of the dot matrix printer illustrating the parts of the cutting mechanism; Figs. 5A and 5B are left side and right side elevational views, respectively, showing the arrangement of the cutting mechanism; and Figs. 6A and 6B are a front view and a side view of a conventional cutting mechanism. Referring now to Fig. 1, a printer 10 is designed as a two station, receipt/slip and journal printer The receipt/slip printing station occupies a front portion 12 and the journal printing station occupies a rearward portion 14 of the printer. A slip table 16 is provided along the left hand side of the printer 10. A front cover 17 swings toward the right to expose certain operating parts of the printer 10. Figs. 2 and 3 are right and left side elevational views and show certain elements of the printer 10 in diagrammatic form. The receipt/slip portion 12 and the journal portion 14 include individual print wire solenoids (not shown) along with a ribbon cassette 18 for the receipt/slip printing station operation and a ribbon cassette 20 for the journal printing station operation. A roll 22 of receipt paper is journaled at the front of the printer and the receipt paper 24 is driven and guided by appropriate pairs of rollers, as 26, 28, 30 and 32 in a path past the receipt/slip printing station for printing operation and for issuance of a receipt 33 after cutting thereof from the receipt paper 24. A supply roll 34 of journal paper is positioned in a cradle at the rear of the printer 10 and the journal paper 36 is driven and guided by appropriate pairs of rollers, as 38 and 40, in a path from the supply roll 34, past the journal printing station, and onto a take up roll 42. A timing plate 43 (Fig. 2) is provided at the receipt/slip printing station for positioning the receipt/slip feed rolls. Fig. 4 is a perspective view of the receipt cutting mechanism according to a preferred embodiment of the present invention. A right side plate 44 and a left side plate 46 provide support for the receipt cutting mechanism. A pair of shafts 48 and 50 are secured to the side plates 44 and 46 and provide support for a carriage 52 that is slidably moved along the shafts 48 and 50 in transverse direction on the printer 10. The carriage 52 is driven in such transverse direction by means of a reversing-type motor 54 which is suitably supported by the right side plate 44. A toothed belt 56 is trained around a pulley 58 on the end of a motor shaft 60 and around a pulley 62 on the end of a lead screw-type drive shaft 64. The drive shaft 64 is coupled by means of a threaded hub 65 associated with the carriage 52 for driving thereof across the printer 10. A knob 66 is secured to the left end of the shaft 64 to be used for turning the shaft in case of a jam or for manually moving the carriage 52 to a desired position. A belt or like resilient member 68 with teeth 69 is stretched across the printer parallel to the shafts 48 and 50 and is secured to the side plates 44 and 46 by suitable means. A pair of rollers 70 and 72 are journaled on a bracket 74 secured to the carriage 52 and are positioned in offset manner to engage with the smooth side of the toothed belt 68. A toothed gear 76 is also journaled on the bracket 74 on the carriage 52 and is positioned under the rollers 70 and 72 to mesh with the toothed belt 68. The rollers 70 and 72 are positioned at different levels relative to the toothed belt 68 and to the toothed gear 76 in order to provide positive contact of the teeth 69 of the belt 68 with the gear 76. A second toothed gear 78 is disposed adjacent and is journaled coaxially with the toothed gear 76 and rotates therewith. The toothed gear 78 engages and meshes with a third toothed gear 80 which is also journaled on the bracket 74. A circular cutting knife or blade 82 is disposed adjacent and is journaled coaxially with the toothed gear 80 and rotates therewith. The cutting blade has an angled cutting surface 84 with an edge 86 arranged to engage with and contact an edge 88 (Fig. 4) of a fixed blade 90 supported in secure manner across the printer 10. Fig. 5A is a left side view illustrating parts of the arrangement of the carriage 52, the toothed belt 68, the rollers 70 and 72, the gears 76, 78 and 80, and the cutting blade 82 in contact with the fixed blade 90 (Fig. 4). Fig. 5B is a right side view illustrating the arrangement of the rollers 70 and 72, the gears 76, 78 and 80, and the cutting blade 82. The gear 76 is positioned to mesh with the teeth 69 on the lower side of the toothed belt 68 and to cooperate with and to be positively driven by the teeth 69 in response to pressure by the rollers 70 and 72 against the belt 68. The different levels of the two rollers 70 and 72 ensure a positive driving force of the gear 76 and of the intermediate gears 78 and 80 and of the cutting blade 82. When the carriage 52 is driven in transverse direction for receipt cutting operation, the teeth 69 on the belt 68 engage with the teeth on gear 76 to rotate such gear. When the carriage 52 is driven to the left, as seen in Fig. 4, the gear 76 is rotated in the clockwise direction. Since the gear 78 is coaxial and on the same shaft as the gear 76, gear 78 is rotated in the clockwise direction. Gear 80, meshing with gear 78, is rotated in the counterclockwise direction. Since the cutting blade 82 is coaxial and on the same shaft as the gear 80, the blade 82 is rotated in the counterclockwise direction. In this regard, when the carriage 52 moves to the left (Fig. 4), the blade 82 rotates counterclockwise which provides an increased cutting force. If the blade 82 rotates clockwise, the cutting force is reduced. Fig. 5B shows the carriage 52 with the bracket 74 supporting the rollers 70 and 72, the gears 76, 78 and 80 and the cutting blade 82. As seen in Fig. 4, the carriage 52 includes a right side plate 92 and a left side plate 94. The support bracket 74 is constructed to be pivotable on a pivot member 96 which is journaled in the side plates 92 and 94. A coil spring 98 is placed on the pivot member 96 and one end 100 of the spring 98 is in contact with the lower surface of an upper portion 102 of the support bracket 74. The other end 104 of the spring 98 is in contact with an angled surface portion 106 of the carriage 52. The coil spring 98 is arranged to provide an urging or biasing force on the support bracket 74 in the counterclockwise direction (Fig. 5B) relative to the position of the carriage 52. The urging force of the spring 98 causes the edge 86 of the cutting blade 82 to bear against the edge 88 of the fixed blade 90 and to ensure engagement of the edges 86 and 88. It is possible that the support bracket 74 may rotate or pivot a slight amount in the clockwise direction (Fig. 5B) by reason of foreign matter sticking to the surface of the receipt paper 24. In order to alleviate this condition, the toothed belt 68 is made of relatively soft material to ensure firm engagement of the gear 76 with the teeth 69 of the belt 68. An alternative to the belt 68 is a metallic rail with teeth firmly engaged with an appropriately positioned gear for driving the cutting blade 82. The rotating velocity of the cutting blade 82 can be made adjustable dependent upon the kind and thickness of the receipt paper 24, and dependent upon wearing of the cutting blade 82 caused by rotation of the blade while in contact with the fixed blade 90. It is also within the concept of the present invention to rotate the cutting blade 82 at a velocity which corresponds to a resulting velocity that is the same as or is slightly faster than a velocity corresponding to the transverse moving speed of the carriage 52. The gear ratio of the associated gears may be changed to change the rotational velocity of the cutting blade 82. An alternative to the intermediate gears is the use of pulleys and a connecting belt to drive the cutting blade 82 in rotational manner. Further, an alternative to the lead screw-type drive shaft 64 is the use of a linear pulse motor to move the carriage 52. Figs. 6A and 6B are a front view and a side view, respectively, of a conventional arrangement for cutting receipt paper. A carriage 110 is provided with a round blade 112 that is driven in the horizontal direction along a guide member 114. The round blade 112 is journaled on a shaft 116 supported on a bracket 118 and the round blade is urged against a fixed blade 120 by a spring 122 on the shaft 116. A receipt (not shown) is cut off by the round blade 112 upon horizontal movement of the carriage 110. It is seen that the round blade 112 is rotated only by frictional force generated during a receipt cutting operation. If foreign material slows or stops the rotation of the blade 112, a smooth cutting operation is not possible, and uneven rotation of the blade 112 causes wearing of such blade. The present invention provides a positive drive for the cutting blade so that the cutting operation is certain and smooth even though foreign material may be present in the cutting area. As a result, the entire cutting surface of the blade 82 is used in the receipt cutting operation so that wearing is reduced and a predetermined cutting force can be maintained for a longer period of time. If desired, the cutting force can be increased to ensure a smoother cutting operation. It is thus seen that herein shown and described is a compact dot matrix printer that includes a receipt cutting mechanism, wherein the cutting blade is caused to be rotated by the external driving force that is used to move the cutting blade carriage. The cutting mechanism provides for superior cutting operation, for even wearing of the blade, and for maintaining a constant cutting force over a period of time.

Claims: An apparatus for cutting a record medium (33) including a rotatable cutting member (82) rotatably mounted on support means (74) movably mounted on a carriage (52), drive means (54,56,64) for moving said carriage (52) in a reciprocal manner along a guide path relative to frame means (44,46) of the apparatus, said rotatable cutting member (82) being operably associated with a fixed cutting member (90) mounted on said frame means (44,46) for cutting said record medium (33) upon driving of said carriage (52) along said guide path, gear means (76,78,80) mounted on said support means (74) and engageable with a resilient elongated toothed member (68) mounted on said frame means (44,46) for rotating said cutting member (82) in response to movement of said carriage (52) along said guide path, and roller means (70,72) for urging said toothed member (68) into engagement with said gear means (76,78,80), characterized in that said roller means (70,72) include a pair of spaced rollers (70,72) journaled on said support means (74) and positioned in offset manner for urging said toothed member (68) into engagement with said gear means (76,78,80). An apparatus according to claim 1, characterized in that said support means (74) is pivotably mounted to said carriage (52), biasing means (98) being coupled with said support means (74) and with said carriage (52) for biasing said rotatable cutting member (82) against said fixed cutting member (90) for ensuring cutting of said record medium (33). An apparatus according to claim 1 or 2, characterized in that said support means (74) includes a bracket (74) for journaling said gear means (76,78,80) and said cutting member (82). An apparatus according to any one of the claims 1 to 3, characterized in that said biasing means (98) includes a coiled spring (98) having one end thereof engageable with said carriage (52) and the other end engageable with said support means (74). An apparatus according to any one of claims 1 to 4, characterized in that said gear means (76,78,80) includes a first gear (76) engageable with said toothed member (68), a second gear (78) coaxial with said first gear (76), and a third gear (80) spaced from and meshing with said second gear (78) and coaxial with said cutting member (82) for rotating thereof. An apparatus according to any one of claims 1 to 5, characterized in that said carriage (52) includes spaced side plates (92,94) for containing said rotatable cutting member (82). An apparatus according to any one of claims 1 to 6, characterized in that said drive means (54,56,64) includes a lead screw (64).

Inventors: YAMAZAKI RYUJI, YOKOTA KATSUYOSHI, YAMAZAKI, RYUJI, YOKOTA, KATSUYOSHI
Applicants: NCR INT INC, NCR INTERNATIONAL INC.
Application year: 1989
Main classification: B41J11
IPC codes: B26D1, B41J11