US2572057A

US2572057A - Alarm device for indicating failure of the paper feed mechanism in teleprinters

Info

Publication number: US2572057A
Application number: US704975A
Authority: US
Inventors: Salmon Reginald Dennis
Original assignee: Creed and Co Ltd
Current assignee: Creed and Co Ltd
Priority date: 1944-03-24
Filing date: 1946-10-22
Publication date: 1951-10-23
Anticipated expiration: 1968-10-23
Also published as: CH281992A; CH267818A; US2480165A; GB582528A; FR55278E; FR928904A

Description

Oct. 23, 1951 R. D. SALMON ALARM DEVICE FOR INDICATING FAILURE OF THE PAPER FEED MECHANISM IN TELEPRINTERS 2 SHEETSSHEET 1 Filed Oct. 22, 1946 Oct. 23, 1951 R. D. SALMON 2,572,057 ALARM DEVICE FOR INDICATING FAILURE OF THE PAPER FEED MECHANISM IN TELEPRINTERS 2 SHEETSSHEET 2 Filed Oct. 22, 1946 Inventor W44! M Ma y Attorney Patented Oct. 23, 1951 UNITED STATES PATENT OFFICE ALARM DEVICE FOR INDICATING FAILURE OF THE PAPER FEED MECHANISM IN TELEPRINTERS Application October 22, 1946, Serial No. 704,975 In Great Britain July 19, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires July 19, 1965 8 Claims.

This invention relates to an alarm device for indicating failure of the paper tape to feed in a teleprinter, more particularly when the tape is of the gummed tape kind.

Heretofore there has been devised a paper feeding mechanism for feeding the tape in a teleprinter, in conjunction with alarm devices for indicating failure of proper operation of the tape feeding mechanism whereby the alarm was given should the feeding rollers fail to grip the paper tape or should the paper tape break, in either of which cases the mechanism would fail to tension the tape.

It sometimes happens, particularly with gummed tapes, that the paper tape becomes stuck in the roll and fails to feed, although it may not break, and the feature of the present invention is to provide in a tape teleprinter, mechanically operated means whereby an alarm device is operated should the tape become gummed in the feed roll or become similarly seized, even though the tape should not actually break.

The invention is particularly suit-able with a teleprinter of the type wherein the tape is to be guided around a printing platen which platen is carried by a hinged frame which, when in closed position, positions the platen in proper printing relation with respect to a series of printing bars. In such a construction, it is necessary therefore, in order to secure proper printing, that the hinged frame which carries the platen, the tape feeding and inked ribbon reversing mechanism, be completely closed, so as to maintain the proper relation between the printing platen, the tape, and the type faces. In addition, an object of the present invention is to arrange the alarm device to be actuated if the frame on which is mounted the paper feeding, ink ribbon and reversing mechanism, is inadvertently left swung away from or not closed up to the typewheel, that is, when not in its normal operative position.

The alarm signal may be audible and/ or visual and the arrangement of the invention acts mechanically and positively without recourse to time relays such as slow-acting relays which have heretofore been required in order to give an alarm.

One embodiment of the invention is hereinafter described and illustrated in Figs. 1, 2 and 3 of the accompanying drawing.

The several figures illustrating the embodiment are:

Fig. 1, a view, with parts broken away, of the frame, on which is mounted the paper feeding,

ink ribbon feeding and reversing mechanism, in its normal operative position of juxtaposition with the typewheel.

Fig. 2, a view of the relevant parts of the paper feeding mechanism including the alarm mechanism shown in relation to the teieprmter but with the supporting framework and cover omitted for the sake of clearness.

Fig. 3, a view of the mounting frame of Fig. 1, swung away from the typewheel.

As shown more clearly in Figs. 1 and 2, the gummed tape 7 is arranged to be taken off a suitable supply reel (not shown) and fed in the direction of the arrow, so that it passes between a pair of jaws and thence as indicated by the dot-dash line it passes around a pulley roller H from which it is partially looped, and passes around the printing platen ll. After leaving the platen H, the tape passes between the feed rollers l8, 19. The feed roller I9 is arranged to be operated in a step-by-step manner by means of a suitable ratchet wheel l9a I and pawl i9b, which in turn are arranged to be operated in timed relation by any suitable mechanism including, for example, the swingable lever 42b as described in detail in co-pending U. S. application, S. N. 589,247, now Patent No. 2,480,165.

The tape guide or jockey roller I1 is attached to a lever 20 which is mounted for rotation at point 2! for pivotal movement in a horizontal plane. The end of lever 20 is urged in a clockwise direction by a suitable spring 41, thus causing roller I1 resiliently to engage the tape 1 so as to maintain it under a predetermined tension. Downwardly depending from lever 20 is a pin 44, which is adapted to engage a trip arm 42, normally held in resilient engagement with pin 44 by a suitable spring 420.. The free end of lever 42 is adapted to engage the latch 48 which is pivotally mounted at 48a. Latch 48 may be held in resilient engagement with the end of arm 42 by a suitable spring 481). Latch 48 has a rectangular opening 19 to permit the arm 42 to pass freely therethrough when said arm is in alignment with said opening. The horizontal position of arm 42 with respect to opening 19, will therefore be dependent upon the position of lever 20, which in turn will be dependent upon the tension in tape 1. The tape when normally tensioned, maintains the lever 20 in such a position that the pin 44 holds the arm 42 in registry with opening 19, so that any movement of the arm 42 perpendicular to the latch 48 as a result of clockwise rotation of member 422), does not disturb the position of this latch. However, the tape'] is over-tensloneo as a result, for example, of ts sticking either at the supply reel or at any other intervening point, it causes the lever zu to be rotated counterclockwise, thus pushing arm 42 to the left so that it is no longer in registry with opening l9. On the other hand; if the tape should actually break at any point, the spring 41 causes the lever to to be rotated clockwise as aresult of which the arm 42 moves to the right of opening is. From the foregoing, it will be seen that the arm as, which may be referred to as the alarm controlling member, can assume three sep arate positions. In one position, corresponding to normal tension of tape 7, it is in alignment with opening iii. In another position,-it.-is to the right of this opening corresponding to a breakage of the tape. In the third position, it is to theleft of opening i9 corresponding to a blocking of the tape at any point in its'i'eeding movement. Arm i2 is pivotally attached at iZd to the member $21) which controls the feeding movement of the ratchet i922. The member 5212 is arranged to be oscillated about a pivot point 620 by the usual tape feeding mechanism. When the member eZb is oscillated in a clockwise direction, it causes *member 42 to push latch ill clockwise. Normally however, the latch 48 is held by its spring set so that its detent i8 is in engagement with the contact controlling lever 80, and the lever 8i) is restrained from closing the alarm circuit contacts e3 The lever 8b is pivoted on a horizontal axis 58 and is held by a spring 5| against the detent 118 on the lower edge of latch 48 whereby latch 58 normally lies in the path of lever Bil.

In the event of failure of proper action of the paper feeding mechanism whereby the mechanism fails to tension the'tape, the end of the trip arm t2 engages latch 48 onone side OI the rectangular hole '39 thereby removing latch 58 from the path of lever 86] so that spring 5i rotates this lever sufficiently, to close alarm contacts 53.

In the event of failure of the paper tape to feed due to gumming of the tape in thefeed roll or similar seizure, the loop oftapep'assing around the printing platen ii will be successively shortened by action of the fe'edingrollers l8, it thereby retracting pulley roller it against spring 4? beyond its normal moved position. Trip arm 42 is then rotatedcounterclockwise, viewedfrom above, by the pin i4, whereby trip arm 42 engages with latch is on the other corresponding side of the rectangular hole i9. Latch 48 is thereby removed from the path of lever 8i] so that spring 5| rotates lever Bi] sufliciently to close alarm contacts 53.

Preferably the machine is provided with an enclosing casing 9 which houses the usual typeselecting mechanism and has a suitable opening through which a selected type bar (not shown) can be moved towards the platen llpas described in application SerialNo. 592,172, filed May 5, 1945, now Patent No. 2,483,4l6, .Hingedly.

attached to the casing 9 isan inverted L'-shaped frame If], the vertical wall of which carries the spools Hi for the inked ribbon o. The horizontal wall of the frame it carries the rotatably mounted platen ll together with the .latch 38 and the tape-feeding mechanism including cle mentsl'l, l8, l9, I9a, i9b, 2fi, 21, 42, lga flb, 48, 48a, 18, 79, as illustrated in Fig. 2, whereas the lever 86 and the alarm circuit contacts 53 are mounted on a suitable fixed frame (not shown) which carries the usual type-selecting mechanism interiorly of easing ,9. It will be seen, therefore, that in order to eifect proper engagement between the platen H, the inking ribbon 6 and the tape 1, it is necessary that the frame id be completely closed. If this frame is not completely closed, the latch F8 on member 38 is not in engagement with the upper end of lever 86 so that this lever is held in its counterclockwise position ,by spring 5i to close the .alarm circuit contacts 53.

Figs. 1 and 3 of the accompanying drawing illustrate respectively the normal operative position of the frame Hi and some opened position to give access to the typewheel which according to the present invention will actuate the alarm signal. This is effected, as follows:

The latch 48 is mounted with the paper feeding mechanism on the'frame it, whereas the pivot 58, carrying the lever Be is mounted. on a fixed portion of the machine. Then, if the frame ii! is moved from its normal position (Fig. 1) to some opened position (Fig. 3) the latch 48 will be moved away from lever all, thereby permitting the spring 5| to rotate the lever 80, thereby closing the alarm actuating contacts 53.

What is claimedis: a

1. Alarm actuating apparatus for use with a tape feeding mechanism comprising tape guiding means, a biasing spring, said means adapted to engage the tape and to have a predetermined normal, lateral position corresponding to normal tape tension, to be laterally shiftable against the tension of said spring in one direction away from said normal position upon sticking of the tape, to be laterally shiftable upon actuation of said spring in the other direction away from said normal positionupon breakage of the tape, an alarm operating element comprising a pair of switch contacts anda pivoted'lever adapted to actuate said contacts, said lever spring-biased to operating position; latching means rotatable about an axis disposed at a right angle to the pivotal axis of said lever, said latching means normally engaging said lever to restrain same from actuating saidedntacts, said latching means provided with an aperture therethrough, trip means, meansto reciprocate said tripmeans against said latching means, and for urging said latching means out of engagement with said lever when said guiding means is in a position otherthan normal, said trip means adapted to pass through the aperture 1 in said latching means only when said guiding means is in normal position, whereby said contacts are actuated when said tape guiding means shifts in either direction from n-ermal position. a

2. A tape feeding mechanism according to claim 1 wherein the means to reciprocate said trip means m r ses adesflfieieb ta f lever, said trip means being p'ivotally attached to said tapefeed lever a pinmovable as a unit tape feeding mechanism as, claimed inclaim 1,

wherein said tape jg ding mea compri e an additional pivotedleverpa pulley roller rotatably mounted at one end of said additional lever, said biasing spring attaehed to theotherend or. i .addiim il rer i .n rmai m gi esai roller into engagement with the tape to tension same, and wherein said latching means com-' prises a latch plate having a detent at one extremity thereof and a pivot at the other extremity thereof, an additional spring for normally urging said plate and detent into engagement with said pivoted lever.

4. A tape feeding control mechanism according to claim 1, wherein said tape guiding means further comprises a pin which abuts against said trip means, and wherein said trip means is pivotally connected at one end thereof to said trip reciprocating means; a further spring adapted to urge said trip means against said pin; said latching means extending transversely and having its aperture in alignment with the other end of said trip means only when the tape is under normal tension, said latching means further comprising detent means in latching engagement with said contact actuating lever.

5. A tape feeding mechanism according to claim 1, wherein said trip means comprises a trip arm having a free end and having its other end pivotally connected to said trip reciprocating means, said tape guiding means comprises a pin in sliding contact with said trip arm, said pin adapted to control lateral movement of the free end of said trip arm with respect to the aperture in said latching means, said trip arm adapted to assume a first position corresponding to alignment with the aperture in said latching means when normal tape tension exists, a second position on one side of the aperture in said latching means when abnormal tape tension exists and a third position on the other side of the aperture in said latching means when no tape tension exists, said latching means comprising a detent to normally hold said contact actuating lever in a position in an unoperated position when said trip arm is reciprocated while in its first lateral position, said detent adapted to release said contact actuating lever to an operated position when said trip arm is reciprocated while in either its second or third lateral position.

6. An alarm control arrangement for the feeding mechanism of a tape printer and the like, comprising means adapted to guide a message tape through said printer, an alarm operating element comprising a pair of normally open alarm circuit contacts and a pivoted lever for operating said contacts, a latch member having two positions in one of which it restrains said lever from closing said contacts and movable to another position where it frees said lever to close said contacts, a. pivotally mounted arm also movable transversely to said latch member, tape feed mechanism for causing said transverse movement of said arm, said arm being arranged to assume selectively one of three different pivoted positions with respect to said latch member, one of said positions corresponding to normal tape tension and in which it is ineffective to move said latch member.

7. An alarm control arrangement according to claim 6, wherein said means adapted to guide a message tape through said printer further comprises a pulley roller, said pivotally mounted arm being engaged by an operating pin for controlling its said three positions; said pin being attached to said roller.

8. A tape feeding control mechanism for tape teleprinters and the like, comprising a platen around which a message tape is adapted to be guided, a pair of tape guides at least one tape guide laterally offset with respect to said platen, means resiliently urging said one guide against the tape to provide a normal tape tension around said platen, an alarm operating element comprising a pair of switch contacts and a pivoted lever spring biased to operating position, means mechanically coacting with said lever to hold it in a position corresponding to normal tape tension whereby said contacts are not actuated, a trip arm, a pin member controlled by said one tape guide for controlling the movement of said trip arm to one of three pivoted positions, a tape feeding control member for reciprocating said trip arm, said mechanical coacting means selectively controlled by the reciprocating motion of said trip arm and in accordance with the pivotal position of said trip arm.

REGINALD DENNIS SALMON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,202,952 Adams Oct. 31, 1916 1,343,910 Evans June 22, 1920 1,361,860 Holt Dec. 14, 1920 2,142,880 Anderson Jan. 3, 1939 2,179,517 Pelosi Nov. 14, 1939 2,214,609 Drake Sept. 10, 1940 2,410,521 Potts Nov. 5, 1946 FOREIGN PATENTS Number Country Date 490,368 Great Britain Aug. 11, 1938