US3610495A

US3610495A - Escapement for card or tape reader

Info

Publication number: US3610495A
Application number: US851331A
Authority: US
Inventors: Noboru Murayama; Shinichi Hirata; Kinichi Yoshikawa
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 1968-08-24
Filing date: 1969-08-19
Publication date: 1971-10-05
Anticipated expiration: 1988-10-05
Also published as: GB1279858A; DE1943128A1; DE1943128C3; DE1943128B2

Abstract

In a card or tape reader of the type in which a ratchet wheel (escapement wheel) is imparted with a continuous torque and its rotation is controlled by controlling a stopper which engages with the teeth of the ratchet (escapement) wheel thereby intermittently feeding a paper tape or card, an electrical circuit arrangement for extending the control time of the stopper and more particularly a stopper control time extension circuit in parallel with a conventional control circuit. When a code or signal indicates that the reader is not required to be stopped, stopper holding current is supplied to a magnet which attracts the stopper. The feeding speed may be remarkably increased.

Description

United States Patent Inventors Appl. No. Filed Patented Assignee Priority ESCAPEMENT FOR CARD 0R TAPE READER 2 Claims, 4 Drawing Figs.

US. Cl 226/24, 226/76, 226/120 IIILCI ..Gllb 15/24 Field of Search [56] References Cited UNITED STATES PATENTS 1,023,797 4/1912 Batdorf 226/76 X 3,181,759 5/1965 Maples 226/76 X 3,460,732 8/ I969 Kallenberg 226/157 X Primary Examiner-Allen N. Knowles Attorney-Burgess, Ryan & Hicks ABSTRACT: In a card or tape reader of the type in which a ratchet wheel (escapement wheel) is imparted with a continuous torque and its rotation is controlled by controlling a stopper which engages with the teeth of the ratchet (escapement) wheel thereby intermittently feeding a paper tape or card, an electrical circuit arrangement for extending the control time of the stopper and more particularly a stopper c0ntrol time extension circuit in parallel with a conventional control circuit. When a code or signal indicates that the reader is not required to be stopped, stopper holding current is supplied to a magnet which attracts the stopper. The feeding speed may be remarkably increased.

PATENTEDUBT 51971 3510495 sum 1 or 2 ESCAPEMENT FOR CARD OR TAPE READER BACKGROUND OF THE INVENTION The present invention relates to a card or tape reader such as a punched card or tape reader and more particularly to an escapement used in the reader.

In the reader of the type described above, an escapement is utilized as a card or tape feed mechanism. Essentially the escapement is such that a ratchet (escapement) wheel is imparted with a force so as to rotate continuously and a stopper pawl or pallet which engages with the teeth of the ratchet (escapement) wheel is so regulated as to intermittently impart the torque of the ratchet (escapement) wheel to a driven shaft. In a conventional paper tape or card reader, a sprocket wheel or pinch roller is carried by a driven shaft which also carried a ratchet wheel through a friction disk and a stopper which engages with the ratchet wheel is controlled by a magnet or the like whereby the paper tape or the card is advanced and stopped for each code or character.

In operation of the magnet, the response or rise time and releasing time are involved. The maximum speed available when the escapement is used is limited by the following relation:

Magnet releasing time+marginal time=time for escaping one tooth of the ratchet wheel and arresting the next tooth. Therefore, the time for feeding one character requires response or rise time=releasing time=marginal time.

In the conventional reader, therefore, the intermittent movement speed of the driven shaft cannot be increased to the speed of the drive shaft however well the characteristics of the magnet may be improved or whatever higher the speed of the drive shaft may be increased as far as the intermittent movement for each character is carried out.

In view of the above, the primary object of the present invention is to increase remarkably the tape or card feed speed by rotating the driven shaft substantially at the same speed with that of the drive shaft when required, thereby eliminating the defects or disadvantages encountered in the prior art.

SUMMARY OF THE INVENTION According to the present invention, in a card or tape reader of the type in which a ratchet wheel is always imparted with a force so as to rotate continuously and its rotation is controlled by controlling a stopper which engages with the teeth of the ratchet wheel, thereby intermittently feeding the paper tape or the card, an escapement is provided which comprises means for extending the stopper control time thereby clearing the stopper from the teeth of the ratchet wheel and in which the stopper-holding current is supplied to a magnet which attracts the stopper when a signal or code represents that the reader is not required to be stopped.

According to the present invention, as means for extending the stopper control time there is provided a stopper control time extension circuit in parallel with a conventional magnet control circuit so that the stopper may remain attracted by the magnet for a time longer than the ordinary stopper-attracting time, thereby permitting the continuous feed of the paper tape or card. According to one embodiment of the present invention, the above-described stopper control time extension circuit comprises of a flip-flop and a Darlington circuit connected in series.

The above and other objects, features and advantages of the present invention will become more apparent from the following description of one example of the prior art and one illustrative embodiment of the present invention with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of an escapement utilized in the prior art and in the present invention;

FIG. 2 is one embodiment of a control circuit according to the present invention;

FIG. 3 is a time chart ofa conventional escapement; and

FIG. 4 is a time chart of the escapement of the present in vention.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a photoelectric-type reader provided with a conventional escapement which is utilized in the present invention. Reference numeral 1 designates a main drive shaft directly connected to an electric motor and driven in the direction indicated by the arrow; 2, a locknut which presses a friction disk 5 against a ratchet wheel 6 through a friction spring 4 and a washer 3; 7, a driven shaft directly connected to the ratchet wheel 6; and 8, a sprocket wheel directly coupled to the driven shaft 7 and provided with sprocket pins or teeth 9 for feeding a card or tape. A tape 10 is provided with feed holes or perforations l1 and punched holes 12 indicating various codes which may be read out optically by a photoelectric element 13 in a manner well known in the art. An armature stopper 14 is adapted to engage with the ratchet wheel 6 and when the armature stopper 14 is attracted by a magnet 15, the stopper 14 is disengaged from the teeth of the ratchet wheel 6 so that the driven shaft 7 is rotated. Upon deenergization of the magnet 15, the armature stopper I4 is returned to its normal position by a return spring 16 so that the stopper I4 engages with the teeth of the ratchet wheel 6, thereby stopping the rotation thereof and consequently the driven shaft. Reference numeral 17 designates lead wires to a coil of the magnet 15.

FIG. 2 illustrates one embodiment of a control circuit for energizing the magnet 15 of the escapement described above according to the present invention.

Reference numerals

20, 21 and 22 designate control terminals; 23, a monostable mul' tivibrator to be energized by a signal from the contact 20; 25. a flip-flop which is set by signal from the terminal 21 and is reset by a signal from the terminal 22; 24 and 26, Darlington circuits which energize the magnet 15 when the monostable multivibrator 23 or the flip-flop 25 is actuated; R and R. are resistor connected in series to the magnet 15. In this case, R R,.

FIG. 3 illustrates a time chart of the intermittent movement by the conventional escapement mechanism while FIG. 4, the time chart of the present invention which permits the continuous feed movement if desired. 1,, (where n=l ,2 8) designates time. 31 designates the feed hole output obtained by reading the feed holes 11 of the tape 10 shown in FIG. 1. Feed holes produce high level outputs while no feed hole produces the low-level output. 32 designates the reading gate signals which represent the time to read out the punched holes 12. When the reading gate signal is at its high level, the punched holes or codes are read out while when the reading signal is at its low level the magnet 15 is controlled. 33 designates the waveform of the output of the monostable multivibrator 23 which is energized if required when the gate signal is at its low level. 34 designates the waveform of the current passing through the coil of the magnet 15. 35 in FIG. 4 designates the waveform of the output of the flip-flop 25.

With reference to FIG. 3, the intermittent movement for each code of the conventional escapement will be described. When the read" instruction is given to the tape reader which is not actuated, the reader gate will be opened for t as indicated by the waveform 32. When the signal of the reader gate is at its low level and when the conditions for continuous operation are not given, the output of the monostable multivibrator 23 in FIG. 2 rises for 1 as indicated by the waveform 33 in FIG. 3, so that the magnet 15 is energized through the Darlington circuit 24. In this case, the current flows through the coil of the magnet 15 as indicated by the waveform 34 in FIG. 3. When the armature stopper 14 is attracted by the magnet 15 so that the tape 10 is transported, the positions of the feed holes 11 are displaced (the displacement starts from the stepped portion of the waveform 34), the feed hole output rises to its high level as indicated by the waveform 31 after 1 and then after t, the feed hole output falls down to the low level and the next code or p'unched holes is read out. After t the magnet is deenergized, but the releasing time lags for time t by a surge suppressor which is normally provided, due to the so-called sticking." However, the armature stopper is released sufficiently before the next tooth of the ratchet wheel passes away, that is within the time 5,. Thus, the reader is returned to its initial condition similar to that before the read instruction was received.

Next the present invention which permits the continuous operation will be described with reference to FIG. 4. The magnet 15 is energized by the rea instruction as described with reference to FIG. 3 and a series of operation steps are cycled. When-it is not required to stop the paper tape or card after the reader having read out one code during the time t during which the reader gate is opened, (for example, in case of the invalid codes or fast-forward codes), the flip-flop 25 in FIG. 2 is set so that the magnet 15 is kept energized continuously through the Darlington circuit 26. Therefore, even when the output of the monostable multivibrator 23 reaches the low level as indicated by the waveform 33, the magnet 15 remains energized by the output of the flip-flop 25 as indicated by the waveform 33. In this case, since the magnet 15 may be kept energized by the holding current which is less than the current required for energizing the magnet, the current is fed through the resistor R whose resistance is far higher than that of the resistor R Thus, the magnet 15 is kept energized by a relatively small current after t, as indicated by the waveform 34.

Now the paper tape may be fed at a speed corresponding to the rpm. of the motor. When the signal representing the Stop instruction is read out, the Stop" instruction is given by the falling or dropping trailing edge of the reader gate pulse L, so that the signal from the reset terminal 22 shown in FIG, 2 resets the flip-flop 25, thereby stopping the holding current to the magnet 15. Thus, the stopper 14 engages with the teeth of the ratchet wheel 6, thereby stopping the tape. in this case, the current is low as shown by the waveform 34 in FIG. 4,

sticking time of the magnet 15 is very shorter as compared with the above-described sticking" time 1 so that the magnet is released in a stable manner within the next time t Thus, it will be understood that the paper tape or the card may be advanced for each code and may be advanced continuously when desired by extending the time for attracting the stopper, so that the readout may be carried out efficiently at the maximum speed.

We claim:

I. In an intermittent movement device for intermittently feeding a paper tape or card of the type in which a ratchet wheel is imparted with a continuous rotational force and the rotation of said ratchet wheel is controlled by controlling a stopper which engages with the teeth of said ratchet wheel, the improvement comprising an escapement having means for extending the control time of said stopper including a series circuit consisting of a flip-flop and a Darlington circuit, which series circuit is connected in parallel to a stopper control circuit.

2. In an intermittent movement device for intermittently feeding a paper tape or card of the type in which a ratchet wheel is imparted with a continuous rotational force and the rotation of said ratchet wheel is controlled by controlling a stopper which engages with the teeth of said ratchet wheel, a magnet is adapted to be energized to attract and maintain said stopper out of engagement with said ratchet wheel, and said tape or card includes openings producing high level output when exposed to reading means, the improvement comprising said tape or card having a predetermined length absent of openings to produce a low-level output when exposed to said reading means; and

circuit means electrically connected with said magnet and responsive to said low-level output, to energize said magnet and hold said stopper in attracted position when said tape or card is rcad out on said predetermined length.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 495 Dated October 5, 1971 Invent I-( Noboru Murayama, et a1.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 28, change to (both instances) Column 2, line 39, change "resistor" to resistors Signed and sealed this 16th day of May 1972.

( SEAL Attsst":

EDWARD I LFLETCHER JR R0 BERT GO'I'TSC HALK Attesting Officer- Commissioner of Patents FORM Po-wso (1069l 1770-149 USCOMM-DC 60376-P69 e u.s. uovsnmasm nznn'me OFFICE: mu 0-s5s-su

Claims

1. In an intermittent movement device for intermittently feeding a paper tape or card of the type in which a ratchet wheel is imparted with a continuous rotational force and the rotation of said ratchet wheel is controlled by controlling a stopper which engages with the teeth of said ratchet wheel, the improvement comprising an escapement having means for extending the control time of said stopper including a series circuit consisting of a flip-flop and a Darlington circuit, which series circuit is connected in parallel to a stopper control circuit.

2. In an intermittent movement device for intermittently feeding a paper tape or card of the type in which a ratchet wheel is imparted with a continuous rotational force and the rotation of said ratchet wheel is controlled by controlling a stopper which engages with the teeth of said ratchet wheel, a magnet is adapted to be energized to attract and maintain said stopper out of engagement with said ratchet wheel, and said tape or card includes openings producing high level output when exposed to reading means, the improvement comprising said tape or card having a predetermined length absent of openings to produce a low-level output when exposed to said reading means; and circuit means electrically connected with said magnet and responsive to said low-level output, to energize said magnet and hold said stopper in attracted position when said tape or card is read out on said predetermined length.