Field of the Invention
The invention relates to a printer feeder for edge-punched record carriers. The printer feeder is formed from a fastening rod and a rotating drive shaft in parallel position. Tractors, placed on the fastening rod and the drive shaft, move in parallel and axially symmetrically to one another.
Background of the Invention
Printer feeders for edge-punched record carriers serve the purpose of pulling and guiding record carriers (e.g., edge-punched paper webs) straight through the printer. A prerequisite for the course of the operation in the printer is a trouble-free feeding of the record carrier stacked in folded layers. Working from the stack is gaining importance due to the increasing processing of continuous forms.
Supporting the fastening rod and drive shaft for the tractors on the printer frame is known from German Published Patent Document DE-PS 25 14 506. However, a later retrofitting of printers already in operation with the device disclosed in this published patent document is not possible because the structural space is otherwise occupied. Thus, already existing printers cannot be retrofitted or can be retrofitted only with considerable difficulties with a feeder for edge-punched record carriers as disclosed in this published patent document. On the other hand, there is a demand for printers optionally with or without paper feeders.
Objects of the Invention
The principle object of the invention is to provide a feeder for edge-punched record carriers which can also be installed on existing printers. Accordingly, the changes in the printer must be kept within narrow limits.
A further object of the invention is to provide a feeder for edge-punched record carriers in which continuous record carriers may be processed troublefree even with an unfavorable location of the paper supply.
A still further object of the invention is to provide a feeder for edge-punched record carriers in which the design of the feeder is suitable for mass production, and the parts may be economically produced and assembled.
Summary of the Invention
The objects of the invention are achieved by a feeder which is made as a self-supporting frame from side supports and which can be connected to the printer frame by means of a pair of suspension hooks provided on each of the side supports in position to engage corresponding fastening bolts. A cover for the drive elements is mounted on at least one of the side supports. A catch is provided on the cover to maintain the feeder in its operating position. The invention makes possible a simple retrofitting of a printer with paper feeder, so that the printer can be supplied at first without a paper feeder.
The connection of the tractor parallel guide with the drive parts to a single unit is advantageous. Accordingly, the cover together with the side supports form a housing, closed to a very large extent, for a gear reduction unit with at least one gear step and several idler gears. The first gear meshes with a gear on the platen shaft, and the last gear of the gear train is connected to the drive shaft.
Production of the feeder is advantageously made economical by journals for the gears being formed on the inside of the cover. These journals have heads which serve as catches between the cover and the side support.
The parallelism of the two side supports and thus of the fastening rod and drive shaft is obtained very accurately by the fastening rod for the tractors being axially adjustable relative to one or both of the side supports.
Precision in guiding the paper is additionally increased by the tractors being provided in each case with guide walls which guide the record carrier. These guide walls extend crosswise to the fastening rod or drive shaft. The guide elements are made as guide walls to correct a skewed entry of the paper web. Adjustment of the tractor to the width of the paper additionally causes an adjustment of the guide walls to the intended paper width.
According to additional features, the necessary volume of the feeder is not increased by the guide walls if the guide walls are retractable to a position parallel to the fastening rod or drive shaft.
Precision in guiding the paper can be improved even further by fastening a wing or lug to the end of the guide walls, extending in each case perpendicularly to the advance direction of the record carrier. These wings or lugs, together with the printer frame, form a guide shoulder for the record carrier. At the same time, this guide shoulder prevents a faulty insertion of the paper width. The guide walls and lugs keep the paper web from being able to move freely between the guide walls, the printer frame, and other printer components.
Guiding of the paper web is further assisted by a movable support for the record carrier being provided on the fastening rod and drive shaft between the tractors.
Brief Description of the Drawings
FIG. 1 is a side view of the feeder in operation position on the printer.
FIG. 2 is a front view of the feeder with sectioned cover and with the printer elements omitted.
Detailed Description of the Presently Preferred Embodiment
A printer 1 has a frame 1a and a print counter support 2. The print countersupport 2 is formed from a platen 2a mounted on a platen shaft 2b. The printer 1 receives a record carrier 3 from a supply bin (not shown). The record carrier 3 enters the printer 1 in the direction signified by the arrow 4 and, after being printed on, leaves the printer 1 in the direction signified by the arrow 5.
A feeder 6 (shown in detail in FIG. 2) is in the operating position in FIG. 1. The feeder 6 is mounted on a self-supporting frame including a side supports 7a and a side support 7b. The side support 7a and 7b are connected by a fastening rod 8 and a drive shaft 9. The drive shaft 9 is rotatably mounted in bearings 9a and 9b. A gear 25 on the drive shaft 9 contains the bearing 9a, and the bearing 9b is contained in a bearing cap. The fastening rod 8 and the drive shaft 9 are parallel to one another. Similarly, the side supports 7a and 7b are parallel to one another.
Tractors 10a and 10b are placed axially symmetrically to one another on the fastening rod 8 and the drive shaft 9. The relative positions of the tractors 10a and 10b can be adjusted for varying widths of the record carrier 3. The tractors 10a and 10b each comprise a continuous belt 11 with inwardly pointing teeth (not shown) and pilot pins 12 sized, shaped, and positioned to engage the pin holes in the selvage of the record carrier 3.
As shown in FIG. 1, side supports 7a and 7b end in upper and lower suspension hooks 13 and 14, each of which is mountable on suitable fastening bolts 15 and 16 on the frame 1a of the printer 1. The weight of the feeder 6 is sufficient in itself to guarantee a secure position to the feeder 6. Still greater security is obtained by a catch 17 which is formed on a cover 18 in the form of an elastic hook 17a. The cover 18 consists of an injectable material (e.g., a plastic), so that the elastic hook 17a can be formed at the same time as the cover 18.
The cover 18, together with the side support 7a, forms a housing 19 for protecting a gear reduction unit 20. As shown in FIG. 1, the gear reduction unit 20 includes a gear step 21, idler gears 21a, 22, and 23, and another gear step 24. The gear 25, which is mounted rotatably on the drive shaft 9, is a component of the gear step 24. A gear 21b, which is a component of the gear step 21, has approximately the same diameter as platen 2a and is likewise mounted on the platen shaft 2b.
The cover 18 has three journals 18b (of which only one is shown) formed on the inside 18a of the cover 18. Idler gears 21a, 22, and 23 are rotatably mounted in the journals 18b. As illustrated in FIG. 2 for the idler gear 23, the side support 7a guides the idler gears 21a, 22, and 23 by a bearing shoulder 18f. Journals 18b end in heads 18c which project through through-holes 18g in the side plate 7a. Each of the heads 18c is provided with a slot 18d and has a shoulder 18e. Accordingly, a catch 26 is produced from the throughhole 18g in the side support 7a, the shoulder 18e, and the slot 18d.
The fastening rod 8 can be axially adjusted by means of setscrews 27 (shown in FIG. 2). The setscrews 27 are supported on the outside by side supports 7a and 7b to obtain a precise parallel position of the side supports 7a and 7b--and, thus, also of the fastening rod 8 in relation to the drive shaft 9.
Guide walls 28 and 29 are mounted on the tractors 10a, 10b, respectively, by joints 30 so that they can swing inwardly in the direction of arrows 31a and 31b, respectively. The guide walls 28 and 29 help to feed the record carrier 3 and also guide the record carrier 3 laterally during operation. In the feed position, the guide walls 28 and 29 are in parallel to the fastening rod 8 and the drive shaft 9.
To guide the record carrier 3 from below (in addition to the lateral guiding of the record carrier 3 by the guide walls 28 and 29), the guide walls 28 and 29 carry wings 32 on their ends. The wings 32 support the record carrier 3 from below. Each wing 32 itself further mounts a lug 33, which, with suitable construction of the printer frame 1a (as shown in FIG. 1), engages a stop 34. Accordingly, a guide shoulder 35 is provided for the record carrier 3.
A further improvement of the guiding for the record carrier 3 is provided by a support 36 (shown in FIG. 2) which can move on the fastening rod 8 and the drive shaft 9 and can always be put in the middle position between the tractors 10a and 10b.