US3096865A

US3096865A - Typewriter escapement mechanism

Info

Publication number: US3096865A
Application number: US155382A
Authority: US
Inventors: James F Smathers
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-11-28
Filing date: 1961-11-28
Publication date: 1963-07-09
Anticipated expiration: 1980-07-09

Description

July 9, 1963 J. F. sMATHERs 3,096,865

TYPEWRITER ESCAPEMENT MECHANISM' Filed Nov. 2s, 1961 2 sheets-sheet 1 July 9, 1963 J. F. sMATHERs v 3,096,865

-TYPEWRITER ESCAPEMENT MECHANISM Filed Nov. 28, 1961 2 Sheets-Sheet 2 JAMES F. SMATHERS INVENTOR.

AGENT United States Patent() 3,096,865 TYPEWRITER ESCAPEMENT MECHANISM James F. Smathers, P.0. Box 1016, Poughkeepsie, N.Y. Filed Nov. 28, 1961, Ser. No. 155,332 9 Claims. (Cl. 197--84) This invention relates to typewriting machines and more particularly to a mechanism ttor moving the carriage thereof in pre-determined increments which are in accordance with the character key which is actuated and is an improvement over similar mechanisms disclosed in my U.S. Patents No. 2,848,091, and 2,904,159.

As is well-known in the typewriter art, the carriage is usually advanced in equal increments for each character key that is actuated. With this arrangement considerable space exists between any two letters, such as, f, i, 1, t and j `as compared with the space between such letters as m, \v, etc. As a result, the spacing between letters is not always uniform, nor is any line utilized to obtain a maximum number of letters, punctuation marks and spaces in each line. It has been found that by providing an escapement .mechanism for the carriage which is capable of :advancing it in Variable increments in accordance with an increment assigned to each letter or mark, the number of characters that can be typed on a page can be increased by 30 to 40 percent. This has been accomplished by providing a space for the lower case letters which is Iequivalent to three increments or units of space, with the exception of the letters L i, 1, t and j and the Iperiod, comma and semi-colon which are assigned two units of space, with the exception of the w which is assigned four units of space, and with the exception of the m which is assigned live units of space. The upper case letters are assigned cfour units of space with the exception of the letter I which is assigned two units of space, with the exception of the letters S and I which are assigned three units of space, and with the exception of the letters M and W which are assigned 4live units of space. This description relates to a standard typewriter key board, as it is well-known in the zart.

In the prior art, escapement mechanisms associated with the carriage for providing :different spacin-gs for various characters on the key board utilized a plurality of pawls for selectively engaging a ratchet wheel which is driven 'by the carriage. The various mechanisms known in the art are so designed that movement of the pawls requires a very heavy `spring to overcome `and move the mass involved. Further, arresting movement of such a mass subjects other parts to severe and recurring shocks. Since the mass of the pawls is relatively large and is usually moved by resilient means, the speed of movement is relatively slow due to the inertia required to start the. mass. Because of this fact and in order to obtain Ia movement of the pawls :and of the carriage which corresponds to or exceeds a m-aximum typing speed, the spring force must be very great and the structure must, likewise, be sufliciently sturdy :and strong.

The present invention overcomes these diliculties, however, in that a single stop pawl is used for engaging the ratchet wheel, the pawl being independent of the ratchet and not moved therewith. As 4a result, the stop pawl can ybe heavy enough to withstand the recurring shocks due to 4stopping the carriage, and its weight is immaterial because it is not moved with the ratchet. Also, the stop pawl or limiting member now carried by the ratchet can be very light and due to the small mass now being moved, the movement can be accomplished at a much :faster rate than has been heretofore possible and, :as stated hereinbefore, by :a much lighter spring. This results in a much more economical structure in that the other elements need not be as sturdy and, in addition, the structure set forth is much simpler and, hence, is more feasible commercially.

3,096,865 Patented July 9, 1963 lCe The escapement mechanism which permits movement of the carriage in accordance with the key which is operated comprises a ratchet which is interconnected by means of gears to the carriage which is ydriven in a letter-feed direction by a spring motor. A groupl of pivotal-ly mounted members is arranged with respect to the ratchet and each member is provided with a stop surface :aligned with -a successive tooth of the ratchet. These surfaces provide a series of preselected stops in .a definite relation to the ratchet and each is selectively positioned in an operative position upon actuation of the character key associated therewith. A control pawl, which is pivotally and slidably mounted with respect to the center of rotation of the ratchet and has a portion vfor engaging a tooth of the ratchet, together with a control member, which is also pivotally mounted with respect to the center of rotation of the ratchet, :are moved in one direction as a unit with the ratchet and in the other direction as a unit independent of the ratchet. The ratchet and the two control members are moved as a unit in the letter-feed direction by the spring motor which I'also moves the carriage and, hence, through suitable gears rotates the ratchet. Movement of the ratchet and the carriage is arrested when a portion of the control member engages the stop pawl latch which is positioned in the path thereof. When a key is actuated, the universal bar actuates la pivoted member arranged with respect to the ratchet to release the stop pawl yfrom the ratchet and move it into a latched position as well as to release the control pawl Ifrom the ratchet and move it into a Ilatched position with respect to the control member. The control pawl and control member are then immediately moved in :an opposite direction by a separate resilient means toward one of the stops corresponding to the key operated, the control pawl being held and retained in a latched position until the stop is engaged by the control member at which time it again moves into engagement with the ratchet.

With this arrangement, the movement of the carriage is determined by the control pawl in that the control pawl is always in the same relation to the stop pawl when the carriage is fully arrested. The amount of movement of the control pawl in the direction opposed to the letter-feed direction is established by one of the designated stops and, hence, measures the number of increments of space allocated to the character just printed with respect to the tooth of theratchet from which the control pawl is released. Since the control pawl is latched to the control member, when moved in the direction opposed to the letter-feed direction, premature reengagement of the control pawl with the ratchet is prevented, the control member releasing the control pawl only upon engagement of one of the stops and thereby assuring reengagement of the proper ratchet tooth by the control pawl. An economical and compact escapement mechanism is therefore obtained and is one which is capable of operating at a much faster rate than heretofore possible.

'Ilhe primary object of `the invention is, therefore, to provide an escapement mechanism in which 'two members cooperate as a single control unit for arresting movement ofthe carriage as well as establishing the amount of movement thereof.

Another object of the invention is to provide an escapement mechanism in which a stop pawl for arresting movement of a carriage ratchet and :a control pawl for establishing the amount of movement of fthe carriage ratchet are separably latched in positions disengaged from the oarriage ratchet fora predetermined interval fto permit Inovement of said carriage ratchet land to prevent reen-gagement of said pawls with said carriage ratchet during said interval.

Yert another object tot the invention is to provide an escapement mechanism in which two members cooperate Y 3 as a unit land are movable with the carriage ratchet tor controlling the amount of carriage movement.

Still another object lof the invention is to provide an escapement mechanism in which the amount of carriage movement -is controlled by two members coacting as a unit and in conjunction with one of a plurality 'of members selected by the character key which is actuated.

A further object ot the invention is to provide an escapement mechanism in which two members are movable as a unit independently with respect toI all other members in one direction and are movable as a unit by the carriage in the other direction.

And still another object lof the invention is to provide Ian escapement mechanism with ia minimum number of elements and which is operable at a high rate of speed and is efficient in operation.

Other objects and advantages derived from the invention will be readily 'apparent to those skilled in the art trom the description which follows.

Reference is now made to the accompanying drawings in which like reference numerals designate like pants and wherein:

FIG. 1 is la vertical section through a typewriter and showing the manner in which the character keys and escapement mechanism are @arranged with respect to the carriage;

FIG. 2 is a partial plan view `ot the escap'ement mechanism and showing the position of the vanions elements when the carriage is fully arrested;

FIG. 3 is a partial plan view of the escapement mechanism and showing the position of the various elements upon actuation of 'one of the keys to release the carriage for movement;

FIG. 4 is a partial plan view of the escapement mechanism showing the position ot the various elements upon engaging a stop and establishing the movement of the carmage;

FIG. l5 is a detail perspective view of the latching member for the pawl shown in FIG. 6;

FIG. `6 is a perspective view showing the pawl for engaging the ratchet to arrest movement of the carriage;

FIG. 7 is la partial section taken on line 7--7 of iFIG. 3 and showing the :arrangement of the two members which .cooperate as a unit and are movable in one direction with the ratchet and independent of the ratchet in the other direction; and

FIG. 8 is :a Kdetail side elevation of the elements shown in FlG. 7 `and showing the arrangement thereof with respect to the ratchet and its drive gear.

While the esoapexnent mechanism is disclosed in connection with a typewriter of the type known as an International Business Machines, Executive Model, typewriter, the invention is not to be limited to this disclosure in that the mechanism is equally well adapted to other applicain which is variable linear advance is desired accordance with preselected conditions. With reference to FIG. l, carriage 10 which is a conventional typewriter carriage, is mounted tor .travel in a horizontal direction by means of iront rail 11 and rear rail 12 and carries a conventional platen roll 13. A spring motor 14 is rotatably mounted on bracket 15 and by means of a tape 16 having one end fixed to carriage 10 moves said carriage in :a letter-direc direction in a manner well-known in the att.

The character type keys only one of which is shown, are pivotally mounted at one end lat 21 and guided at other end in the slots 22 in comb 23 extending between the side frames. Springs 24, one for each key, maintain the keys in their normal position.

A conventional power-driven roller 25 is provided to drive spring-loaded cams 26 (one cam for each type key `20), Aas is well-known in the art and disclosed in my U.S. Patent No. 1,600,252. The cam levers 27 `are pivotally mounted lon a rod 28 and cams 29 are pivotally mounted on their respective levers at 30, springs 31 maintaining their respective cam levens and cams in proper position. Sliding pawls 32 are each provided with an elongated slot 33 and are mounted on cam levers 27 by rivets 34 in said slots. Springs 35 arranged between cam levers 27 land pawls 3.2 maintain pawls 32 between lugs 36 on keys 2.0y and cams 29.

A selector comb 37 is arranged beneath bracket 38 and with respect to rod 39 and cam stops 40 yare adjnstably mounted on bracket 38. Type bars 41 are pivotally mounted at 42 in pivotal corn-b 43 and are connected by links 44 to their corresponding cam levers 27. Rod 39 beneath comb 37 engages the underside of selectors 45 which are pivotally mounted at one end Iat 46 to cam levers 27 and slidably engage the slots in comb 37. Templet rods 47, 48 and 49 `are mounted in bracket 50 and carry

rocker arms

51, 52 and 53 to which clevis

rods

54, 55 and 56 are connected, respectively. It should be noted at this point that selectors 45 are provided for keys 20 which require ya spacing other than normal, in other words, more than three increments of space.

In operation, an operator will strike a key 20' which requires a spacing other than normal, for example, the lower case w which requires four increments of space. Striking key 20 causes it to pivot about 21 `and thereby tension spring 24 and, at the same time, is guided by slot '22 in comb 23 during its movement. Lug 36 engages pawl 32 to force cam 29 against the continuously rotating drive roll 25 whereby cam lever 27 is actuated and through link 44 causes type bar 41 to pivot on rod 42 and strike platen 13 to print the required w. The pivotal movement of type `bar 4l causes the type bar to strike universal bar 57 which shifts toward the back ot the typewriter. Cam lever 27, simultaneously with the actuation loi type bar 41, draws selector 45 toward the rear of the typewriter and rotates rod 48. With this action, olevis rod 55 is moved toward the front of the typewriter. A complete disclosure of the structure and tunction of selector 45 rand lits related elements can be derived from my abovementioned U.S. Patent 2,904,159.

Clevis rods

54, 55 `and 56 are connected to extensions 58, 59 `and 60 on rods mounted in bracket 61, only one of said rods, namely rod 62, being shown in FIG. l. Similar extensions, not shown, lare fixed to the other ends of said rods which, in turn, are connected to a group of selector stops 185 which are designated by the same numerals `and actuated in the same manner -as described in my U.S. Patent 2,904,159. Also universal bar 57 is `connected by llink to wing 104 on actuating member 100 whereby the escapement mechanism 70 is yactuated in a manner to be described hereinafter.

The escapement mechanism 70 is driven by means of carriage 10. This is accomplished by means of rack 71 which is fixed to the carriage, las shown in FIG. 1, and which meshes with pinion 72 on the upper side of plate 73. Pinion 72 is rotatably mounted on the same shaft with ratchet 74 which is on the other side of plate 73, as shown in FIG. 8. The teeth of ratchet 74, in effect, measure the increments of movement of carriage 10. In other words, the central `angle formed by any two successive teeth is equivalent, when transposed into linear movement through pinion 72 and rack 71, to one increment of space for each character. As stated hereinabove,

two increments are required for the minimum space allotted to the period, f, i, etc., and such minimum space is, therefore, equivalent to the angular movement of two ratchet teeth. In the same manner, three spaces or increments are equivalent to three teeth, etc.

With reference particularly to FIGS. 2-8, the escapement mechanism 70 comprises the ratchet 74 anda number of members which Iare actuated in conjunction with the selector stops designated generally by the numeral 185. A stop pawl 8i), which is pivot-ally mounted at 81 `adjacent ratchet 74, -is provided with a nose 82 for engaging the teeth of ratchet 74 and with an extension 83 to which one end of spring 84 is attached. A release pin S5 is carried by said stop pawl which is also provided with a notch 86 arranged adjacent nose 82 for a purpose about to be described, said stop pawl being shown in detail in FIG. 6. A latch .member 90 is shown in detail in FIG. 5 :and is pivotally mounted at 91 adjacent ratchet 74 with the end 92 connected to the other end of spring 84. The end 93 is provided with a down-turned lug 94 and an upstanding lug 95, the lug 94 being of a width for engaging notch 86 in stop pawl 80. With reference to FIG. 2, it will be noted that spr-ing 84 tends to move stop pawl 80 and latch member 90 in opposite directions with respect to their respective pivotal `axis.

An actuating member 100 is pivotally mounted at 101 and is provided with `a leg 102, an upstanding lug 103, and a wing 104 which has a slot 105 for receiving the end of link 150 in a manner as disclosed in my US. Patent 2,904,159. The leg 102 is arranged for engaging pin 85 on stop pawl 80 to release the pawl in a manner to be described hereinafter. Member 100 iis urged against link 150 by spring 106, see FIGS. 2-4.

Ratchet 74 is mounted on the shaft to which pinion 72 is secured and the ratchet and pinion rotate asa unit when moved by rack '71. Control pawl 110 is mounted with respect to the axis of rotation of ratchet 74 `and is provided with a slot 111 which penmits said pawl to move not only radially with respect to said ratchet but also independently thereof about its axis. Control pawl 110 has a down-turned portion 112, see FIG. 7, which -serves to engage the teeth of ratchet 74, a shoulder 113, an extension 114 to which one end of -spring 115 is attached, lan extension 116 to which one end of spring 117 is attached, and a leg 118 which is arranged to be engaged by lug 103 on member 100.

A control member 120 is pivotally mounted over control pawl 110 with respect to the axis of rotation of ratchet 74 and is freely movable Iabout said axis. The end of control member 120 is provided with a stop lug or nose 121 for engaging the surface of one of the selector stops designated `by the numeral 185. Intermediate the end of control member 120 and extension 114 on pawl 110, two down-turned

lugs

122 and 123 are formed, one on each side of said control member.

A group of selector stops 185, which `as noted above are the same as those `disclosed in U.S. Patent 2,904,159, are located adjacent ratchet 74. These stops comprise the stop levers 250 iand 251 pivotally mounted at 252 on expander arm 242, stop lever 251 being pivotally connected at 260 to the link 256 and by spring 266 to expander arm 242, the stop lever 253 mounted `at 254 on expander arm 242 and pivotally `connected at 294 to arm 292, and a fourth stop 255 formed in the end of expander karm 242. As explained in the aforementioned patent, the surface 671 of lever 253 is normally in the path of stop lug 121 on member 120 to provide a normal three units of space for lower case letters and when a normal four units of space `for upper case letters is required, surface 661) is moved into the path of lug 121, as described in my abovementioned patent. When `a type key 20 associated with a character requiring other than three units of space (lower case) or four units of space (upper case) is depressed, one of the stops 251 (two units), 256 (auxiliary three units) or stop 25S (five units) will be positioned in the path of lug 121 as described in `detail in the iabove-mentioned patent.

With reference to FIG. 2 which shows the escapement in the carriage arresting position, that is, the position in which carriage cannot 'be moved in a letter-feed direction, the nose 32 of stop pawl 8@ is in engagement with la tooth of ratchet 74 and the lug 94 of latch member 90 is seated in notch 86 of said pawl. In this position, the edge of control member 120 abuts lug 95 on latch member 99 and the portion 112 on control pawl 110 is in engagement with a tooth of ratchet 74. Since the force exerted on ratchet 74 is one which tends to urge it in a counterclockwise direction and spring 115, which has its other end connected to control member 120, tends to rotate rnember 120 in a clockwise direction, the shoulder 113 on pawl .is within lug 122. Also, spring 117 pulls control pawl 110 in a radial direction toward the -axis of ratchet 74 to hold yportion 112 in engagement with the tooth of ratchet 74.

When a key 20 is depressed, the respective type bar 41 is moved toward the platen 13 and at the same time the universal bar 57 moves the link 150 in a direction toward the escapement mechanism, as viewed in FIG. l, and toward the axis of ratchet 74, as viewed in FIGS. 2-4, Depending on the number of units of space required by the key 20 which has been actuated, the proper or corresponding stop 185 will be positioned in the path of lug 121. Since the operation of the escapement mechanism 70 is the same irrespective of the key which is actuated, let it be assumed that the actuated key is associated with a lower case character requiring the normal three units of space. In this case, surface 671 of stop lever 253 will be arranged in the path of lug 121, as shown in FIG. 4. As link 151) is moved toward the axis of ratchet 74, actuating member 101) is moved in a counter-clockwise direction inasmuch as link 150 is in engagement with the slot 1415 in wing 104 thereof. Lug 103 then engages leg 118 of control pawl 110 and leg 102 engages pin 85 on stop pawl 813. With further movement of actuating member 1G11, control pawl 110 is moved radially by member 100 due to slot 111 and portion 112 is disengaged from the tooth of ratchet 74. As control pawl 110 is moved, shoulder 113 clears lug 122 just prior to release of portion 112 from the ratchet tooth. At the instant of full release of portion 112, spring 115 pivots control member to the right and causes lug 122 to move under shoulder 113'thereby holding control pawl 110 in a fully disengaged position from ratchet 74. Control pawl 110 and actuating member 126 are then moved as a unit about the axis of rotation of ratchet 74 in a clockwise direction by means of spring 117 until portion 121 abuts the surface 671. lControl pawl 110 continues to move in a clockwise direction due to spring 117 and shoulder 113 rides off of lug 122, spring 117 then moving control pawl 11) in a radial direction toward the axis of ratchet 74 so portion 112 engages a tooth thereof.

As control pawl 11) is released from ratchet 74, leg 192 is moved into engagement with pin 85 to release nose 82 of stop pawl 8) from ratchet 74 and to release lug 94 on latch member 99 from notch 86. Lug 94 is disengaged from notch 86 before nose 82 leaves the tooth with which it is engaged and, as a result, spring 84 moves latch member 91B in a counter-clockwise direction so lug 94 engages and remains in engagement with the portion of stop pawl 841 immediately behind nose S2, as shown in FIG. 4. When nose 82 is fully released, latch member 90 holds stop pawl Sil in a fully disengaged position with respect to ratchet 74. With reference to FIG. 4, it will be noted that when control pawl 1115 and control member 120 are moved in a clockwise direction by spring 117, leg 118 rides off of lug 1113 only after a predetermined angular movement of said members. This predetermined movement is equivalent to at least two teeth of ratchet 74 to ensure that nose 112 cannot engage ratchet 74 in the event shoulder 113 and lug 122 should fail to engage to hold or latch control pawl 1111 and control member 120 for movement as a unit in the direction opposed to the letterfeed direction.

At this point, it should be pointed out that the release of stop pawl 80 from ratchet 74 occurs at substantially the same time as the release of nose 112. However, it is preferable if the release of nose 11-2 occurs just before that of nose 82. Due to the fact that control pawl 110 and control member 120 are very light in weight and can be so because they are not utilized to arrest ratchet 74, the movement of these members as a unit in a clockwise direction by spring 117 is very fast. As a result,

nose 112 is capable of being engaged with a tooth of ratchet '74 as determined by one of selector stops 185 by the time carriage 1t) is moved by spring motor 14 and its motion is transmitted from rack 71 to pinion 72 and, hence, to ratchet '74. The position of the various escapement elements at this time is shown in FIG. 4. As described in my U.S. Patent No. 2,904,159, key 20 initiates the release of escapement mechanism 7i) through link 150, the positioning of the proper selector stop 185 in the path of stop lug 121 and the movement of the corresponding Ytype bar 41 by the power roll 25. As a result the full release of the escapement mechanism 7) occurs just after the type bar 41 has struck the platen roll 13. ln other words, the movement of the carriage 10 occurs after the letter has been printed and the amount of movement of the carriage in the letter-feed direction corresponds to the number of increments of space required for the letter just printed. Hence, as type bar 41 returns to its normal position, as shown in FIG. 1, link 150 is withdrawn and spring 106 moves actuating member Iii@ in a clockwise direction with said link. At the point that lug 103 is clear of leg 113, ratchet 74 has commenced to move in a counter-clockwise direction carrying control pawl 110 and control member 120 therewith.

As carriage 1t) moves in a letter-feed direction, ratchet 74 is rotated in a counter-clockwise direction as viewed in FIGS. 24, and because nose 112 is in engagement with a tooth thereof, control pawl 110 and control member 129 are moved therewith as a unit in a counter-clockwise direction, the left hand edge of control pawl 110 engaging lug 122. With reference to FlG. 3, the left hand edge of control member 120 engages lug 95 on latch member 90 and the impact of the engagement rocks member 90 in a clockwise direction, thereby disengaging the lug 94 from 'behind the nose S2 of stop pawl 80 and moving member 90 into a position in relation to notch 86. With the release of stop pawl S0 from latch member 90, spring 84 causes stop pawl 80 to move in a clockwise direction so nose 82 engages a tooth of ratchet 74 to arrest movement of carriage 10. The arrangement of the various elements is such that the third successive tooth from the one previously engaged on ratchet 74 will now be engaged by the nose SZ of stop pawl 80. The number of teeth moving past stop pawl 30 will be determined by the movement of control pawl 110 in a clockwise direction as determined by the key which has been actuated and the corresponding selector stop 185 which is positioned in the path of nose 121 on control member 120. Since the relation of nose 82 on stop pawl 80 with respect to nose 121 of control pawl 120, when said pawls are in engagement with a tooth of ratchet 74, is always the same, the number of teeth moved past nose 82, when ratchet 74 is free, will be the same as the number of teeth which nose 121 moves past, when control pawl 1Z0 is moved in the direction opposed to the letterfeed direction.

Since the actual stopping of carriage 10 is accomplished by stop pawl Si) and it is merely moved into and out of engagement with ratchet 74, stop pawl 80 can be made suiiiciently heavy to withstand the continually recurring impact of arresting the carriage. On the other hand, control pawl 110 and control member 12d merely meter the movement of carriage 10 and, as a result, can be light in weight, thereby permitting the use of a spring 117 which is capable of moving control pawl 114) and control member 120 las a unit and independent of ratchet 74 at a very high speed. This is 4accomplished by moving control pawl 110 and control member 120 in a clockwise direction against the appropriate stop 185 and moving pawl 110 into engagement with the corresponding tooth of ratchet 74 before the spring motor exerts sufficient torque to commence the movement oi' carriage 1i). As described hereinabove, the stop pawl Sti is held in a latched or inoperative position duning movement of the carriage until released by control member 121i and control pawl 11i)` is held in a latched or inoperative position during movement in a direction opposed to the letter-feed direction. In each instance, the pawls Sil and are held in such inoperative positions against the action of

resilient members

34 and 117 which are urging the pawls toward ratchet 74. The structure described hereinabove therefore provides an escapement mechanism which is capable of fully controlling as well as varying the carriage movement at the maximum typing speed.

Since modiications and changes in the escapement mechanism described herein may be suggested to those skilled in the art, the invention is not to be limited by the disclosed embodiment but is of a scope as defined by the appended claims.

Having now particularly described my invention, what I desire to secure by Letters Patent of the United States and what I claim is:

1. A dev-ice for varying the movement of a typewriter carriage in accordance with the character key which is actuated, comprising drive means operatively connected to said carriage for moving said carriage in a letter-feed direction, a driven member operatively connected to said carriage, a stop pawl pivotally mounted adjacent said driven member and normally engaging said driven member for arresting movement of :said carriage, a latch member pivotally mounted in spaced relation to said stop pawl for engaging and holding said -stop pawl when it is moved into a position disengaged from said driven member to release said carriage, a plurality of stops arranged adjacent said driven member -in spaced relation to s-aid stop pawl and selectively actuated in accordance with the character key which is actuated for establishing the movement of said carriage in said letter-feed direction, a control pawl having a 4radial slot for mounting said control pawl with respect to the axis of rotation of said driven member for radial and oscillatory movement, said control pawl normally engaging said driven member and adapted tot be disengaged from said driven member for movement in a direction opposite to said letter-feed direction independently of said driven member to engage said driven member in a predetermined relation to the disengaged point for movement with said driven member in said letter-fed direction, a control member pivotally mounted with respect to the axis of said driven member and operatively coupled to said control pawl, said control member holding sa-id con-trol pawl disengaged from said driven member and lbeing moved in t-he direction opposite to said letter-feed direction with said control pawl for engaging the selected stop and releasing said control pawl to engage said driven member and being movable in said letter-feed direction with said control pawl `for engaging said latch member to release said stop pawl, resilient means operatively connected toI said control pawl for moving said control pawl and said control member .as a unit in the direction opposite to said letter-feed direction, when said control pawl is released from said driven member, sol said control member engages the selected stop and said control pawl engages said driven member before said carri-age movement is commenced, and means lresponsive to the character key which is actuated for releasing said stop pawl from said driven member and said control pawl from said driven member to initiate a predetermined carriage movement in said letter-feed direction.

2. A Idevice for varying the movement of a typewriter carriage in accordance with the character key which is actua-ted, comprising drive means. operatively connected to said carriage for moving said carriage in a letter-feed direction, Ian escapement ratchet operatively connected to said carriage and movable thereby, a stop pawl adjacent said ratchet Iand normally engaging said ratchet for holding said carriage against movement in said letter-feed direction, a latch member adapted to engage said stop pawl -for holding said stop pawl in an inoperative position, a control pawl pivotally mounted with respect to said ratchet and normally engaging said ratchet for Inovement therewith in a letter-feed direction, a control member pivotally mounted with respect to said ratchet and movable with said control pawl, -said control member being adapted to engage said control p-awl for holding said control pawl in a position disengaged from said ratchet during movement :in a direction opposite to said letterfeed direction, a group of stops selectively connected to said character keys for establishing the movement of said carriage in accordance with the actuated key, means operatively connected to said control pawl for moving said control pawl and said control member as a nnit in a direction yopposite to said letter-feed direction, when said control pawl is disengaged from said ratchet, and an actuating member movable by sa-id keys, when actuated, for disengaging said stop pawl from said ratchet and movi-ng said stop pawl into engagement with said latch member and for disengaging said control pawl from said ratchet and moving said control Ipawl into engagement -with said control member, whereby said control member releases said control pawl, upon engaging the selected stop, for engagement with said ratchet and movement therewith in a letter-feed direction and said control member releases said stop pawl, npon engaging `said latch member, for arresting movement of said ratchet and said carriage in a letter-feed direction.

3. A device in accordance with claim `2. wherein said control pawl is provided with a portion at the extremity thereof `for engaging said ratchet so as to he moved therewith in said letter-feed direction and is adapted to be disengaged from said ratchet, upon movement of said control pawl in a radial direction, for movement in the direction opposite to said letter-feed direction by said moving means.

4. A device in laccordance with claim 2 wherein said control member is provided at the extremity thereof with a portion for engaging the selected stop, when moved in a direction' opposite to said letter-feed direction, and intermediate its length with :a lug on each side thereof for engaging opposite sides of said control pawl yfor movement therewith, one of said lugs engaging said control pawl, when said control pawl is moved in a radial direction, for holding said control pawl in a position disengaged `from said ratchet, whereby said control pawl and said control member are moved as a unit in said one direction.

5. A device in accordance With claim- 2 and including means on said control pawl for engaging said actuating member to hold said control pawl disengaged from said ratchet during at least a portion of the movement of said control pawl in a direction opposite to said letter-feed direction.

6. A device for varying the movement of a typewriter carriage in accordance with the character key which is actuated, `comprising drive means operatively connected to said carriage for moving said carriage in a letter-feed direction, a driven member operatively connected to said carriage and rotatable upon movement of said carriage, means pivotally mounted adjacent said driven member for normally engaging said driven member to hold said carriage against movement in said letter-feed direction and adapted to be moved to a position disengaged from said driven member to free said carriage for movement, a plurality of stops arranged adjacent said driven member in spaced relation to said engaging means and selectively actuated in accordance with the character key which is actwated for establishing the movement of said carriage, a control pawl having an elongated slot for mounting said control pawl with respect to the axis of rotation of said driven member so as to provide radial and oscillatory movement thereof, said control pawl normally engaging said driven member and being adapted to be ldisengaged therefrom for movement in a direction opposite to said letter-feed direction independently of said driven member to engage one of said stops and reengage said driven member and for movement in said letter-feed direction with said driven member to actuate said engaging means for movement to its normal position, a control member pivotally mounted with respect to the axis of rotation of said driven member and operatively fconnected to said control pawl for moving said control pawl in a direction opposite to said letter-feed direction :and against the selected stop to engage said driven member before said drive means has commenced to move said carriage, and means responsive to the character key which is actuated for releasing said enga-ging means from said driven member :and moving said engaging 'means to said position disengaged from said driven member and for releasing said control pawl from said driven member.

7. A device in accordance With claim 6 wherein said control member includes means thereon for engaging said control pawl whereby said control pawl and said control member are movable as la unit in the direction opposite to said letter-.feed direction and in said letter-feed direction.

8. A device in accordance with claim 6 wherein said control pawl is provided With a portion at the extremity thereof for engaging said driven member so as to be moved therewith in said letter-feed direction yand disengageable from said driven member, upon. movement of said control pawl in a radial direction, for movement in the direction opposite to said letter-feed direction by said control member.

9. A device in accordance with claim 6 wherein said control member is provided at the extremity thereof with a portion for engaging the selected stop, when moved in fthe direction opposite to said letter-feed direction, and intermediate its length with a lug on' each side thereof for engaging opposite sides of said control pawl for movement therewith, one of said lugs engaging said control pawl, when said control pawl is moved in a radial direction, for holding said control pawl in a position disengaged from said driven member -whereby said control pawl `and said lcontrol member are moved as a unit in the direction opposite to said 1etter-feed direction.

References Cited in the tile of this patent UNITED STATES PATENTS 1,359,465 Piersen Nov. 16, `1920 2,202,565 Reid May 28, 1940 2,848,091 Smathers Aug. 19, 1958

Claims

1. A DEVICE FOR VARYING THE MOVEMENT OF A TYPEWRITER CARRIAGE IN ACCORDANCE WITH THE CHARACTER KEY WHICH IS ACTUATED, COMPRISING DRIVE MEANS OPERATIVELY CONNECTED TO SAID CARRIAGE FOR MOVING SAID CARRIAGE IN A LETTER-FEED DIRECTION, A DRIVEN MEMBER OPERATIVELY CONNECTED TO SAID CARRIAGE, A STOP PAWL PIVOTALLY MOUNTED ADJACENT SAID DRIVEN MEMBER AND NORMALLY ENGAGING SAID DRIVEN MEMBER FOR ARRESTING MOVEMENT OF SAID CARRIAGE, A LATCH MEMBER PIVOTALLY MOUNTED IN SPACED RELATION TO SAID STOP PAWL FOR ENGAGING AND HOLDING SAID STOP PAWL WHEN IT IS MOVED INTO A POSITION DISENGAGED FROM SAID DRIVEN MEMBER TO RELEASE SAID CARRAIGE, A PLURALITY OF STOPS ARRANGED ADJACENT SAID DRIVEN MEMBER IN SPACED RELATION TO SAID STOP PAWL AND SELECTIVELY ACTUATED IN ACCORDANCE WITH THE CHARACTER KEY WHICH IS ACTUATED FOR ESTABLISHING THE MOVEMENT OF SAID CARIAGE IN SAID LETTER-FEED DIRECTION, A CONTROL PAWL HAVING A RADIAL SLOT FOR MOUNTING SAID CONTROL PAWL WITH RESPECT TO THE AXIS OF ROTATION OF SAID DRIVEN MEMBER FOR RADIAL AND OSCILLATORY MOVEMENT, SAID CONTROL PAWL NORMALLY ENGAGING SAID DRIVEN MEMBER AND ADAPTED TO BE DISENGAGED FROM SAID DRIVEN MEMBER FOR MOVEMENT IN A DIRECTION OPPOSITE TO SAID LETTER-FEED DIRECTION INDEPENDENTLY OF SAID DRIVEN MEMBER TO ENGAGE SAID DRIVEN MEMBER IN A PREDETERMINED RELATION TO THE DISENGAGED POINT FOR MOVEMENT WITH SAID DRIVEN MEMBER IN SAID LETTER-FED DIRECTION, A CONTROL MEMBER PIVOTALLY MOUNTED WITH RESPECT TO THE AXIS OF SAID DRIVEN MEMBER AND OPERATIVELY COUPLED TO SAID CONTROL PAWL, SAID CONTROL MEMBER HOLDING SAID CONTROL PAWL DISENGAGED FROM SAID DRIVEN MEMBER AND BEING MOVED IN THE DIRECTION OPPOSITE TO SAID LETTER-FEED DIRECTION WITH SAID CONTROL PAWL FOR ENGAGING THE SELECTED STOP AND RELEASING SAID CONTROL PAWL TO ENGAGE SAID DRIVEN MEMBER AND BEING MOVABLE IN SAID LETTER-FEED DIRECTION WITH SAID CONTROL PAWL FOR ENGAGING SAID LATCH MEMBER TO RELEASE SAID STOP PAWL, RESILIENT MEANS OPERATIVELY CONNECTED TO SAID CONTROL PAWL FOR MOVING SAID CONTROL PAWL AND SAID CONTROL MEMBER AS A UNIT IN THE DIRECTION OPPOSITE TO SAID LETTER-FEED DIRECTION, WHEN SAID CONTROL PAWL IS RELEASED FROM SAID DRIVEN MEMBER, SO SAID CONTROL MEMBER ENGAGES THE SELECTED STOP AND SAID CONTROL PAWL ENGAGES SAID DRIVEN MEMBER BEFORE SAID CARRIAGE MOVEMENT IS COMMENCED, AND MEANS RESPONSIVE TO THE CHARACTER KEY WHICH IS ACTUATED FOR RELEASING SAID STOP PAWL FROM SAID DRIVEN MEMBER AND SAID CONTROL PAWL FROM SAID DRIVEN MEMBER TO INITIATE A PREDETERMINED CARRIAGE MOVEMENT IN SAID LETTER-FEED DIRECTION.