| 摘要 |
799,303. Typewriters &c. RUF-BUCHHALTUNG AKT.-GES. Feb. 4, 1955 [Feb. 6, 1954], No. 3399/55. Class 100(4) In a front feed apparatus for forms in typewriting and accounting machines a movable sensing element J120 or K120, Figs. 5, 9 projects into a paper guide slot J20 or K20 respectively so that when a paper is sensed a connected electrical control member starts the driving of a motor to feed the paper into required printing position. This may be to the first line printing position or to a subsequent line indicated by a punch mark which is detected by the apparatus. After typing, the motor, through an electrical circuit arrangement, is reversed to effect line spacing or eject tne paper, and when the last line on the paper has been typed, carriage return causes automatic ejection of the sheet. As shown, the apparatus relates to the feeding of two papers and separate and indepenent feeding apparatus is provided for each, the various parts relating to back and front papers have prefixes J and K respectively. Each sensing element 120, Fig. 9, comprises a block pivotally mounted between the flanges of a support 125. A stop 122 on the block prevents pivotal movement by an incoming card so that the support 125, mounted on an actuater arm 153 itself has to move. This causes the closing of electrical contacts 151 operating an electromagnet which effects movement of the arm 153 to shift the sensing device clear of the slot 20. Contacts 152 now close operating a further relay and switches which shift a detent J40, Fig. 4, clear of a notched wheel J21 on the feeding wheel shaft J15 and starts the electric motor to feed the paper. In the above arrangement, the sensing element acts as a buffer for the paper to check the impact with the feed wheels. Feeding stops when the first printing line on the paper is reached, which is predetermined by a variably positionable pin J50, this pivots a lever J51, closes contacts J54 to operate other relays and contacts to stop the motor and release the detent arm J40 which drops into the next notch on the wheel J21. To eject the paper after typing an entry, a button (231 not shown) is pressed and a carriage return movement made. This operates a relay e.g. K190, Fig. 5, and a punch K191, K192, to effect a perforation (in the form of a semicircular scale remaining attached to the paper), causes detent J40 to be lifted, and operation of the electric motor is reversed to eject the paper. If it is required to type on the next line, the carriage is returned but button J31 is not pressed, the motor being energized through cam J25 and its electrical contacts. When the last line on the paper has been used a pin J260, Fig. 4, has reached and operated contacts J261 so that when a carriage return movement is made the sheets are automatically ejected. If required, the papers may be ejected without carriage return. In order that a paper may be fed to a position marked by the perforation, a detector e.g. J104 is provided in the form of a spring fixed to a strip (102 not shown) vertically sliding in a supporting plate 100, Fig. 7. In the lowermost position of the strip the detectors are deflected from the path of the paper and permits the leading edge of the paper to pass. As soon as the pin J80 releases the locking member J84 the strip is lifted so the detector J104 is operative and an electric contact associated with the strip is conditioned so that when the detector finds a perforation in the paper the contacts close and the motor is stopped. |
