US3618738A

US3618738A - Vertical paper feed for a drafting typewriter

Info

Publication number: US3618738A
Application number: US878126A
Authority: US
Inventors: Richard G Boyatt; George T Williams
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 1969-11-19
Filing date: 1969-11-19
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09
Also published as: CH512331A; DE2056564A1; BE756419A; FR2071707A5; JPS4918729B1; GB1260258A

Abstract

A drafting typewriter is provided for typing notes and dimensions on large sheet material. An improved paper feed provides for selective slow, fast, forward, or reverse running movement of the paper to locate an area where typing is desired. This movement is effected through the use of an electric motor that is at all times connected to the paper feed mechanism. The same motor is employed to provide incremental forward and reverse stepping motion of the paper feed mechanism to define adjacent printing lines through the use of a displacement measuring transducer.

Description

United States Patent 72] Inventors Richard G. Boyntt;

George T. Wllllams, both of Lexington, Ky. [21] Appl. No. 878,126 [22] Filed Nov. 19, 1969 [45] Patented Nov. 9, 1971 [73] Assignee International Business Mnelilnes Corporation Armonk, N.Y.

[54) VERTICAL PAPER FEED FOR A DRAFTING TYPEWRITER l1 Cllims, 9 Drnvrlng Figs.

[52] U.S.C1... 197/114R. 197/122, 197/127 R, 318/597, 318/685 5| 1nt.Cl. 1341119/76 so FieldoiSearch 197/114, 127, 133. 122; 318/305, 597. 598, 685; 696

[56] References Cited UNITED STATES PATENTS 2,667,613 |/|954 Trevitt 318/305 2,825,620 3/1958 Sperry et al..... 197/133 X 2,842,249 7/1958 Morgan et a1... 197/133 2,885,053 5/1959 Davidson 197/114 X Primary Examiner-Ernest T. Wright, Jr. Attorneys-Hamlin and .Iancin and E. Ronald Colfman ABSTRACT: A drafting typewriter is provided for typing notes and dimensions on large sheet material. An improved paper feed provides for selective slow, fast, forward, or reverse running movement of the paper to locate an area where typing is desired. This movement is effected through the use of an electric motor that is at all times connected to the paper feed mechanism. The same motor is employed to provide-incremental forward and reverse stepping motion of the paper feed mechanism to define adjacent printing lines through the use of a displacement measuring transducer.

IHRESHOLD 001111101 PATENIEDNnv BIB?! 3.618.738

' sum 1 0F 3 INVENTORS RICHARD G. BOYATT GEORGE T. WILLIAMS ATTORNEY.

SHEET 2 [If 3 THRESHOLD CONTROL PATENTEnunv 9 |97l SHEET 3 0F 3 FIG. 5'

VERTICAL PAPER FEED FOR A DRAFIING TYPEWRITER BACKGROUND OF THE INVENTION Location of a specific area of a sheet for printing has traditionally been a manual function in both office typewriters and drafting typewriters. The job of locating a general printing zone also ordinarily has coupled with it the task of precise horizontal alignment. While it has been known to employ one feed device for ordinary incremental line feeding and a separate device for continuous feeding of fonns, for example, the present invention has obtained both of these functions from a single feed device to thus automate the printing line locating function in a relatively simple but efficient manner.

DISCLOSURE OF THE INVENTION Our invention provides an electric motor that is continuously connected to a typewriter platen for driving the typewriter platen in forward or reverse directions, at a fast or slow speed for an indeterminate length run, or in line space increments. As the motor is continuously connected to the platen, backlash and clearances inherent in a clutched system are avoided with the result of improved precision. Continuous run motion of the paper is accomplished simply by the use of appropriate switching logic that allows the operator to run the motor in a desired direction at a desired speed until the desired printing line has been reached. During typing of lines, a detent device is effective as is usual in typewriters to maintain a reliable printing line and to precisely define the space between adjacent printing lines. Line spacing is accomplished through an automatic motor control that employs a displacement-measuring transducer. Displacement of the platen itself is thus measured and the motor operation terminated when a line space has been accomplished.

Our invention also provides a relatively simple mechanical displacement transducer employing a disc that rotates with the electric motor. The disc is normally retained at a home position and moves with the motor to a further home position. A mechanical probe cooperates with the disc to detect arrival of the disc at a home position to thereby operate appropriate switching logic to terminate motor operation. In an alternative embodiment of our invention, selection is also made possible of either a full or half-line space by the addition of a further feedback stage to the mechanical position transducer to allow it to operate either between adjacent or nonadjacent home positions.

These and other objects, features, and advantages of our invention will be more apparent from the following description of a specific but illustrative embodiment of the concepts of our invention wherein reference is made to the accompanying drawing of which:

FIG. 1 is a perspective view of a drafting typewriter having a paper feed mechanism constructed in accordance with our invention;

FIG. 2 is a schematic circuit diagram illustrating the controls employed in the typewriter shown in FIG. 1;

FIG. 3 is an enlarged perspective view of the paper feed mechanism of the typewriter shown in FIG. 1 including a portion of the typewriter keyboard;

FIGS. 4a through 4e are progressive operational views of a portion of the paper feed mechanism shown in FIG. 3; and

FIG. 5 is a perspective view of a portion of the mechanism shown in FIG. 3 as modified to embody an alternative selective halfor full-space operation.

Referring now to FIG. 1 there is shown a typewriter or printer including a keyboard 11 and a printing mechanism 12. The printing mechanism 12 is preferably like that disclosed in U.S. Pat. No. 2,919,002. The typewriter 10 further includes a paper-handling system 13 comprising a laterally displaceable carriage 14 that supports a movable paper-feeding platen or roll 15 adjacent the printing mechanism 12. As disclosed in U.S. Pat. No. 3,578,131, letter feeding or spacing between individual print characters is accomplished by lateral displacement of the printing mechanism 12. Lateral movement of the carriage 14 is employed to present different areas of a very large sheet of paper or other material P to be typed on to the printing mechanism 12. This arrangement is useful, for example, in printing on engineering drawings as large as 48 inches in horizontal dimension.

Vertical feeding of paper P is accomplished by rotation of platen 15 to print successive lines or to locate different areas for typing. Vertical paper feed is controlled from the keyboard 11 which includes a manually actuatable incremental control member or forward line space key 16, a manually actuatable incremental control member or reverse line space key 17, a manually positionable fast run control member or key 18 and a manually positionable slow run control member or key 19. All of these

keys

16, 17, 18, and 19 are arranged to control a selectively energizable reversible capacitor start, capacitor run AC electric motor 20.

The motor 20 is continuously interconnected with the platen 15 through a gear transmission 30 that comprises motor pinion 31, speed reduction gear 32, a translating pinion 33 that is slidably mounted on a square shaft 34 to provide power transmission to the moving carriage 14, pinion 35,

idler gears

36, 37, and 38, and an output gear 39 that is securely connected to the platen 15. At the opposite end of the platen 15 is a detent mechanism 40 (see also FIG. 3) including line space detent wheel 41 that defines specific angular positions of the platen 15, a detent pawl 42, and detent status control mechanism 43.

The details of the controls for motor 20 and detent mechanism 40 are shown in FIGS. 2 and 3. The

line space keys

16 and 17 and the

run keys

18 and 19 control the extent, amount and direction of energization of the motor 20. These

keys

16, 17, 18 and 19 operate through a number of secondary motor control switches including motor direction control switch 21, motor run control switch 50, a further motor control or auto stop switch 60, a transducer control clutch switch 61, a detent control switch 44, and

holding circuit switches

22 and 23.

Direction control switch 21 and holding switch 23 are normally positioned to a forward run condition by a direction control bias spring 24. Switch 23 is thus normally open and direction control switch 21 is connected with forward winding 25 of the motor 20. A direction control logic relay 26 is activated when a reverse direction is selected from the keyboard 1 1 in response to closure of either reverse line space switch 62 or of

reverse run switches

51 or 52 by their

respective keys

17, 18, or 19. Upon such closure, holding switch 23 is closed and direction control switch 21 is transferred to connection with reverse motor winding 27.

Run control switch 50 is normally open thus preventing energization of motor 20. Clutch control switch 61 is also normally open to maintain clutch-activating electromagnet 63 (see also, FIG. 3) in an inactive condition.

Switches

50 and 61 are both operated by logic relay 53 to close upon selection of either of the

run control keys

18 or 19 via

key switches

51, 52, 54, or 55. Following closure of clutch control switch 61, electromagnet 63 is activated after a short delay imposed by a capacitor 56 to close detent control switch 44 and to disengage normally engaged clutch 64 (see FIG. 3). Closure of switch 44 activates electromagnet 45 (see also, FIG. 3) of the detent control mechanism 43 to pivot bellcrank 46 counterclockwise and drive arbor 47 axially away from detent wheel 41 to disengage the normally engaged detent wheel 41 from the platen 15.

The speed of motor 20 is controlled by a threshold circuit 70 (FIG. 2) that interrupts the current supply from AC input 71 to output lines 710 periodically as required to maintain the motor speed at a desired level. Output lines 71a are connected to the selected active motor winding 25 or 27 via switch 21. The circuit 70 responds to a speed-sensing device such as a generator coil 72 within the motor 20 that produces a control voltage Be as modulated by a selected resistance 73 or 74. Resistance 73 is placed in the control circuit by closure of either of the fast-run

switches

75 or 76. Resistance 74 is placed in the circuit by closure of either of the slow-run switches 77 or 78. Resistance 79 is continuously active and functions to control speed during incremental operations when neither of the

run control keys

18 or 19 is displaced. Circuit 70 operates in response to voltage Ec exceeding a predetermined threshold to temporarily interrupt current flow to the motor 20 upon an overspeed condition. As the speed reduces to an acceptable level, current flow is again reinitiated. It is to be understood that while the type of motor control thus described is preferred, it forms no part of our invention which can be implemented by a variety of known motor speed control arrangements.

The incrementing motor control or auto stop switch 60 and holding switch 22 are normally open and are closed upon activation of an electromagnet 65 (see also, FIG. 3) in response to closure of either forward line space switch 66 or reverse line space switch 62 by their

respective keys

16 or 17. A displacement transducer 80 (see FIG. 3) controls opening of auto stop switch 60 and holding switch 22 upon measurement of a predetennined increment of travel of the platen 15. The transducer 80 includes a displaceable member or disk 81 that is normally mechanically coupled to the motor 20 by the clutch 64. Electromagnet 63 is connected to declutching arm 67 in opposition to a spring 68 to sever the mechanical connection provided by clutch 64 when it is desired to perform a continuous run operation.

Disk 81 includes a pair of home position indicative slots 82. A translatable probe 83 normally is received within one of the slots 82 and moves to a rightward limit defined by the slot 82 under power of a spring 84. In this position, auto stop switch 60 and holding switch 22 are allowed to open by arm 85 of the probe 83. Probe 83 is moved leftwardly out of the slot 82 and against spring 84 by the electromagnet 65. Electromagnet 65 is connected to the probe 83 through a single-action device including a pawl 86 that is pivoted to a frame bracket 87 and is driven counterclockwise against an end of a bellcrank 88 that is pivotally connected to the probe 83 and normally biased clockwise by a spring 89. A pawl 86 pivots, its angular motion carries it below a cutout portion 89a of the bellcrank 88 to sever the connection between electromagnet 65 and the probe 83. The probe 83, thus, is free to return rightwardly under the power of its spring 84. Since leftward movement of probe arm 85 closes auto stop switch 60, motor 20 has immediately commenced rotation and thus has displaced the slot 82 from its position of alignment with the probe 83. Accordingly, the probe 83 will not be pennitted to return fully rightwardly although released by pawl 86.

As more clearly shown in FIGS. 40 through 4e a reentry control device 90 may be employed to insure that probe 83 will not reenter the slot 82 prior to significant rotation of the motor 20. Device 90 comprises a radially extending shield 91 that is movable angularly with respect to the disk 81 through limits established by a pair of

abutments

92 and 93. Shield 91 extends radially outwardly of the disk 81 to provide an edge or lip 94 by which the shield 91 can be actuated as later described. A pair of leaf springs 95 act against a corresponding pair of tabs 96 on the device 90 to urge the shield 91 toward centered alignment covering the slots 82.

Referring now specifically to FIG. 4a, the disk 81 and probe 83 are shown in a position corresponding to that of FIG. 3. The right-hand leaf spring 95 is urging shield 91 clockwise upwardly against the probe 83. When probe 83 is withdrawn by electromagnet 65 (FIG. 3) as shown in FIG. 4b, the shield am 91 immediately pivots clockwise by its bias from leaf spring 95 to cover the slot 82. Even if probe 83 were immediately released and permitted to return rightwardly, it would not enter slot 82 due to its encounter with shield 91. As shown in FIG. 4c rotation of disk 81 by motor 20 displaces the slot 82 clockwise and will allow the probe 83 to come to rest against the peripheral edge of the disk 81 under urging of its spring 84. The same condition pertains as disk 81 continues its rotation and approaches the slot 82 as shown in FIG. 4d. The

probe 83 will encounter the edge or lip 94 of the shield 91 as shown in FIG. 42 to displace the shield 91 from its position over slot 82 and thus permit probe 83 to reenter the slot 82 moving rightwardly underthe influence of its spring 84 thus returning to a condition like that of FIG. 4a. Immediately upon rightward movement of the probe 83, auto stop switch 60 is opened to terminate current supply to the motor 20 and interrupt rotation. The distance the motor 20 has travelled during displacement of disk 81 corresponds to movement of the platen 15 by a distance of one line space or vertical index. It can be appreciated that due to the symmetry of the disk 81, probe 83, and shield device 90, the distance measuring is performed substantially identically in either the forward or reverse direction.

OPERATION OF THE MECHANISM SHOWN IN FIGS. 1 THROUGH 4 Movement of fast run control member 18 toward its forward active position F closes switches 54 and 76 (See FIG. 2). Switch 76 selects resistance 73 to control the motor speed to a fast velocity. Switch 54 initiates motor operation by closing switch 50 through operation of logic relay 53 and disconnects the detent wheel 41 from the platen 15 by activation of electromagnet 45 through closure of switch 61 and delayed closure of switch 44. When the typing zone has been reached, key 18 is manually returned to its central or inoperative position to thus

open switches

54 and 76 to terminate motor operation by opening switch 50 through deactivation of logic relay 53. Electromagnet 63 which has disconnected transducer by operating clutch 64 to its disconnected condition is dropped after a delay induced by capacitor 56 to thus restore the normal incremental operating mode of the mechanism. Upon deactivation of electromagnet 63, switch 44 is opened to reconnect the platen 15 with detent wheel 41.

Slow forward motion is accomplished in a similar manner by movement of control level 19 to its forward operating position F to close

switches

55 and 78. The difference in operation being the selection by switch 78 of the slow speed control resistance 74 to produce a slow motor control.

If it is desired to select reverse fast or slow continuous run motion, the appropriate control member, for example, key 18, is displaced to its reverse operating position R to close the

switches

51 and 75. In addition to selecting the fast control resistance 73 and initiating motor operation by closure of switch 50, all as previously described, switch 51 further activates reverse control electromagnet 26 to transfer switch 21 to the reverse winding 27 of the motor 20. Switch 52 also transfers the switch 21 when control member 19 is displaced to its reverse operating position R.

Depression of forward line space key 16 initiates operation of the motor 20 at a speed controlled by permanent resistance 79. The motor 20 is energized however by closure of switch 60 through activation of electromagnet 65 upon closure of forward index switch 66.

Turning to FIG. 3, it will be recalled that electromagnet 65 pulls pawl 86 against bellcrank 88 to withdraw the probe 83 from the slot 82 in disc 81. This withdrawal motion closes the switch 60 to initiate operation of motor 20 through forward winding 25. Electromagnet 65 is automatically disconnected from the probe 83 as pawl 86 pivots downwardly clear of the bellcrank cutout portion 89a. Probe 83 thus is freed to return rightwardly by its spring 84, although such motion is prevented by the shield 91 (see FIG. 41)) or the disc 81 (see FIG. 46). Switch 60 thus is retained in its closed condition even though electromagnet 65 may be deenergized. As disc 81 is rotated, shield 91 (see FIG. 4d) encounters the side edge of probe 83 and is displaced away from the slot 82. Probe 83 is allowed to fall into slot 82 as the disc 81 reaches its home position. This motion opens switch 60 to terminate operation of motor 20. Had reverse index switch 17 been depressed, the operation would have been similar with the exception of electromagnet 26 being also operated to transfer direction switch 21 thus activating reverse coil 27 of the motor 20. Switch 23 also would have been closed by electromagnet 26 such that, upon closure of switch 22 by electromagnet 65, a holding circuit is provided through

switches

22 and 23 to the electromagnet 26 to maintain it active until tennination of the operation by opening of

switches

60 and 22.

MODIFICATION FOR SELECTIVE FULL OR HALF SPACE OPERATION In FIG. 5 there is shown a modification of the mechanism of FIG. 3 to accomplish selective half or full vertical spacing. Half-spacing may be desirable, for example, in typing subscripts or superscripts or for typing fractional numbers such as one-half. The mechanism of FIG. 5 includes a displacement transducer 80' that is quite similar to the displacement transducer 80 in FIG. 3 and includes a modified displaceable member 81 having four home positions defined by slots 82. Rotation of displaceable member 81' between adjacent home positions corresponds to one-half a line space and between opposite or alternate slots 82' corresponds to one full line space. A modified probe 83' is actuated directly from an electromagnet 65' upon initiation of either a full or half-forward or reverse line space operation returned by a spring 84. A feedback device like that disclosed in US. Pat. No. 3,514,729 is connected to the disc 81' for selecting between full and halfline space operation. The device includes a magnetic face 101 that is magnetized into four regions 102, separated by sharp transition zones 103. A normally closed reed switch 104 is positioned adjacent the magnetic face 101 in the field of the magnetic regions 102. The reed switch 104 is connected to suitable selective counting logic 105 and indicates motion of the disc 81' by opening upon passing each transition zone 103. The transition zones 103 are oriented approximately 45 out of phase with the reed switch 104. Accordingly, in a half-space operation, electromagnet 65 is deenergized upon opening of the reed switch 104 for the first time. This allows spring 84' to urge probe 83' toward the detecting position where it will fall into the immediately adjacent slot 82' to allow opening of switches 60' and 22' which correspond to

switches

60 and 22 shown in FIGS. 2 and 3. If a full space index is selected, the electronic logic 105 is conditioned to maintain electromagnet 65' energized until reed switch 104 opens for the second time. This allows the disc 81 to rotate past the first home position slot 82 thus enabling measurement of a full line space.

Having thus described concepts of our invention and a specific illustrative embodiment thereof, we define and limit the subject matter sought to be patented solely by the following claims:

1. In a printer having movable feed means engaging material to be printed on and a selectively energizable motor continuously drivingly interconnected with said feed means wherein the improvement comprises:

a manually positionable run control member having an operative position and an inoperative position, first motor control means responsive to movement of said run control member to its operative position for energizing said motor to feed said material and responsive to movement of said run control member to its inoperative position for deenergizing said motor to terminate feed of said material at the will of the operator,

a manually activatable incremental control member,

a displacement transducer,

means operatively connecting said displacement transducer to said motor for movement therewith, and

second motor control means responsive to activation of said incremental control member for energizing said motor independently of said first motor control means, and including means responsive to said displacement transducer for terminating said independent energization of said motor.

2. A printer as defined in claim 1 further comprising motor direction control means for selecting either forward or reverse operation of said motor.

3. A printer as defined in claim 1 wherein said displacement transducer comprises a displaceable member having at least one home position and means responsive to movement of said displaceable member to a home position thereof for generating a control condition, and

said means responsive to said displacement transducer comprises means responsive to said control condition.

4. A printer as defined in claim 3 wherein said displaceable member comprises a rotatable disk.

5. A printer as defined in claim 3 wherein said means for generating a control condition comprises a mechanical probe differentially cooperable with said displaceable member to assume either of two detecting positions in dependence respectively upon said displaceable member being or not being in a home position, and said second motor control means comprises:

means responsive to activation of said manually activatable incremental control member for moving said probe from its home-detecting position to the other detecting position thereof and means for energizing said motor so long as said probe remains in said other detecting position.

6. A printer as defined in claim 1 wherein said motor is electrically energizable.

7. In a printer having movable feed means engaging material to be printed on, a detent mechanism operatively connected with said feed means for defining specific positions thereof, and a selectively energizable motor continuously drivingly interconnected with said feed means wherein the improvement comprises:

a manually positionable run control member,

first motor control means responsive to movement of said run control member to and from an operative position for respectively energizing and deenergizing said motor to selectively feed variable lengths of said material,

a manually activatable incremental control member,

a displacement transducer,

means operatively connecting said displacement transducer to said motor for movement therewith,

second motor control means responsive to activation of said incremental control member for energizing said motor independently of said first motor control means, and including means responsive to said displacement transducer for terminating said independent energization of said motor,

detent status control means for selectively rendering said detent mechanism effective or ineffective, and

means responsive to at least one of said control members for operating said detent status control means to render said detent mechanism effective at all times except whenever said run control member is in an operative position.

8. In a printer having movable feed means engaging material to be printed on and a selectively energizable motor continuously drivingly interconnected with said feed means wherein the improvement comprises:

a manually positionable run control member displaced to and from either of two operative positions and an inoperative position,

first motor control means responsive to movement of said run control member to and from its operative positions for respectively energizing and deenergizing said motor to selectively feed variable lengths of said material,

a manually activatable incremental control member,

a displacement transducer,

second motor control means responsive to activation of said incremental control member for energizing said motor independently of said first motor control means, and including means responsive to said displacement transducer for terminating said independent energization of said motor, and

motor direction control means comprising means controlled selectively alternatively in dependence upon which one of its operative positions said run control member is displaced to for selecting respectively either forward or reverse operation of said motor.

9. A printer as defined in claim 8 wherein said first motor control means further comprises means to select varied amounts of energization of said motor to cause said motor to operate at selectively different rates of speed.

10. in a printer having movable feed means engaging material to be printed on and a selectively energizable motor continuously drivingly interconnected with said feed means wherein the improvement comprises:

a manually positionable run control member,

a first manually activatable incremental control member,

a second manually activatable incremental control member,

a displacement transducer,

second motor control means responsive to activation of said first incremental control member for energizing said motor independently of the said first motor control means, and including means responsive to said displacement transducer for terminating said independent energization of said motor, said second motor control means being also responsive to actuation of said second incremental control member for energizing said motor independently of said first motor control means, and

motor direction control means comprising means controlled selectively in dependence upon which of said first and second incremental control members is activated for alternatively selecting respectively either forward or reverse operation of said motor.

11. In a printer having movable feed means engaging material to be printed on and a selectively energizable motor continuously drivingly interconnected with said feed means wherein the improvement comprises:

a manually positionable run control member,

a manually activatable incremental control member,

a displacement transducer,

means operatively connecting said displacement transducer to said motor for movement therewith and comprising a selectively engageable clutch, resilient means normally urging said clutch into motor-transmitting engagement, and an actuator responsive to said run control member being in an operative position to overcome said resilient means and sever said normal motion-transmitting engagement of said clutch, and

second motor control means responsive to activation of said incremental control member for energizing said motor independently of the said first motor control means, and including means responsive to said displacement transducer for terminating said independent energization of said motor,

# t i t i

Claims

2. A printer as defined in claim 1 further comprising motor direction control means for selecting either forward or reverse operation of said motor.
3. A printer as defined in claim 1 wherein said displacement transducer comprises a displaceable member having at least one home position and means responsive to movement of said displaceable member to a home position thereof for generating a control condition, and said means responsive to said displacement transducer comprises means responsive to said control condition.
4. A printer as defined in claim 3 wherein said displaceable member comprises a rotatable disk.
5. A printer as defined in claim 3 wherein said means for generating a control condition comprises a mechanical probe differentially cooperable with said displaceable member to assume either of two detecting positions in dependence respectively upon said displaceable member being or not being in a home position, and said second motor control means comprises: means responsive to activation of said manually activatable incremental control member for moving said probe from its home-detecting position to the other detecting position thereof and means for energizing said motor so long as said probe remains in said other detecting position.
6. A printer as defined in claim 1 wherein said motor is electrically energizable.
7. In a printer having movable feed means engaging material to be printed on, a detent mechanism operatively connected with said feed means for defining specific positions thereof, and a selectively energizable motor continuously drivingly interconnecTed with said feed means wherein the improvement comprises: a manually positionable run control member, first motor control means responsive to movement of said run control member to and from an operative position for respectively energizing and deenergizing said motor to selectively feed variable lengths of said material, a manually activatable incremental control member, a displacement transducer, means operatively connecting said displacement transducer to said motor for movement therewith, second motor control means responsive to activation of said incremental control member for energizing said motor independently of said first motor control means, and including means responsive to said displacement transducer for terminating said independent energization of said motor, detent status control means for selectively rendering said detent mechanism effective or ineffective, and means responsive to at least one of said control members for operating said detent status control means to render said detent mechanism effective at all times except whenever said run control member is in an operative position.
8. In a printer having movable feed means engaging material to be printed on and a selectively energizable motor continuously drivingly interconnected with said feed means wherein the improvement comprises: a manually positionable run control member displaced to and from either of two operative positions and an inoperative position, first motor control means responsive to movement of said run control member to and from its operative positions for respectively energizing and deenergizing said motor to selectively feed variable lengths of said material, a manually activatable incremental control member, a displacement transducer, means operatively connecting said displacement transducer to said motor for movement therewith, second motor control means responsive to activation of said incremental control member for energizing said motor independently of said first motor control means, and including means responsive to said displacement transducer for terminating said independent energization of said motor, and motor direction control means comprising means controlled selectively alternatively in dependence upon which one of its operative positions said run control member is displaced to for selecting respectively either forward or reverse operation of said motor.
9. A printer as defined in claim 8 wherein said first motor control means further comprises means to select varied amounts of energization of said motor to cause said motor to operate at selectively different rates of speed.
10. In a printer having movable feed means engaging material to be printed on and a selectively energizable motor continuously drivingly interconnected with said feed means wherein the improvement comprises: a manually positionable run control member, first motor control means responsive to movement of said run control member to and from an operative position for respectively energizing and deenergizing said motor to selectively feed variable lengths of said material, a first manually activatable incremental control member, a second manually activatable incremental control member, a displacement transducer, means operatively connecting said displacement transducer to said motor for movement therewith, second motor control means responsive to activation of said first incremental control member for energizing said motor independently of the said first motor control means, and including means responsive to said displacement transducer for terminating said independent energization of said motor, said second motor control means being also responsive to actuation of said second incremental control member for energizing said motor independently of said first motor control means, and motor direction control means comprising means controlled selectively in dependence upon whiCh of said first and second incremental control members is activated for alternatively selecting respectively either forward or reverse operation of said motor.
11. In a printer having movable feed means engaging material to be printed on and a selectively energizable motor continuously drivingly interconnected with said feed means wherein the improvement comprises: a manually positionable run control member, first motor control means responsive to movement of said run control member to and from an operative position for respectively energizing and deenergizing said motor to selectively feed variable lengths of said material, a manually activatable incremental control member, a displacement transducer, means operatively connecting said displacement transducer to said motor for movement therewith and comprising a selectively engageable clutch, resilient means normally urging said clutch into motion-transmitting engagement, and an actuator responsive to said run control member being in an operative position to overcome said resilient means and sever said normal motion-transmitting engagement of said clutch, and second motor control means responsive to activation of said incremental control member for energizing said motor independently of the said first motor control means, and including means responsive to said displacement transducer for terminating said independent energization of said motor.