US2904158A

US2904158A - Power-operated office machine

Info

Publication number: US2904158A
Application number: US767559A
Authority: US
Inventors: Hess Hans
Original assignee: Olympia Werke AG
Current assignee: Olympia Werke AG
Priority date: 1957-10-27
Filing date: 1958-10-16
Publication date: 1959-09-15
Anticipated expiration: 1976-09-15

Description

H. HESS POWER-OPERATED OFFICE MACHINE Sept. 15, 1959 s Sheets- Shet 1 Filed Oct. 16, 1958 Dim mm 1N VEN TO R Ha n s Hess fag Pa fanfj nt Sept. 15, 1959 h HESS 2,904,158

I POWER-OPERATED OFFICE MACHINE Filed Oct. 16, 1958 5 Sheets-Sheet 2 Sept. 15, 1959 HESS 2,904,158

POWER-OPERATED OFFICE MACHINE Filed Oct. 16, 1958 3 Sheets-Sheet 3 IN VEN 70 Hcins Hess United States Patent POWER-OPERATED OFFICE MACHINE Hans Hess, Wilhelmshaven, Germany, assignor to Olympia Werke A.G., Wilhehnshaven, Germany The present invention relates to a device for line spacing power-operated typewriters and similar oflice machines having an electrically driven carriage return niechanism.

It has been proposed to employ an electrically operated carriage return mechanism as the drive means for the line spacing operation, whereby this line spacing operation is performed either independently of a carriage return movement or followed by a subsequentcarriage return upon actuation of separate keys.

This mechanism may be used as the line spacing apparatus in either fully or partially electrically-operated machines. In both types of machines, a line spacing key which is adapted to trigger the line spacing operation independently of the carriage return step also serves to actuate a mechanical locking device which is utilized for locking the carriage return mechanism when said key is depressed. However, the electric control mechanisms in these two types of machines differ from one another. In semieleetric machines, two relays controlling an electric circuit are employed for coupling the carriage return device to a motor through the intermediary of a magnetic clutch disposed in said circuit. These relays are actuated by means of pairs of shunted contact elements provided for the line spacing key and the carriage return key, respectively.

In contradistinction, completely electrically operated machines employ only one relay provided with a pair of holding contacts. This relay can only be energized by actuation of the carriage return key, whereupon a pair of operating contacts for this same relay serves to close the electric circuit for the magnetic clutch. A switch is connected in parallel to this pair of operating contacts, said switch being adapted to be closed only by the line spacing key, whereby the circuit of the magnetic clutch is directly closed independently of the relay.

Consequently, separate electric circuits had to be provided for the carriage return and the line spacing. In addition to this, it was difiicult to obtain a precise operation of the successive steps of this device. For example, occasionally, the line spacing was interrupted upon premature release of the respective control key prior to completion of the switching steps.

It is, therefore, an object of the present invention to provide improved means for line spacing a machine adapted to operate independently of, or immediately before, a subsequent carriage return operation.

It is another object of the invention to provide a new and improved carriage return operation and the electric circuit controlling the same.

It is a further object of the present invention to provide a common electrical circuit for initiating a line spacing operation independent of a carriage return move- I I It is a still further object of the. invention to provide Patented Sept. 15, 1959 "ice means adapted to complete the line spacing step independently of the release of a depressed key.

It is a further object of the invention to provide means to lock the carriage until the line spacing step is completed irrespective of releasing of the key prior to completion of the line spacing step.

It is an additional object of the invention to provide means controlling the rate of energization of a relayto enable the line spacing mechanism to adequately prepare for a subsequent line spacing operation.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

In the drawings:

Figure 1 illustrates schematically a perspective view of a carriage return mechanism and line spacing device-ac.- cording to the present invention;

Figure 2 shows diagrammatically the electric control circuit for the mechanism and device illustrated in Figure 1.

Figure 3 is a fragmentary front view showing in detail the construction of the carriage locking lever and its associated upright lever forming part of the carriage locking mechanism, pursuant to the present invention;

Figure 4 is a sectional view taken along line lV- -IV of Figure 3, showing the connection between a control lever and its associated upright lever.

General description The present invention may be embodied in typewriters or like machines of various types. For the purpose of illustration, the invention is shown in an electrically-operated typewriter. The drawings illustrate only enough of the typewriter structure to assist in illustrating and explaining the manner in which the device may be successfully usedin an electric typewriter.

Referring now in detail to the drawingsand, more particularly, to Figure 1, there is shown a magnetic clutch 1 adapted to positively couple a drawband reel 2 to rotatable shaft 3a driven by a continuously running electric motor 36. A drawband 4, wound about and carried by the reel 2, is guided by means of grooved pulleys S'and 5a, said band being looped at one end and secured to a pin 7 supported by a leg 7a of a line spacing lever 8. This lever 8 serves to effectuate the line spacing operation which moves a work sheet to a new position for further typing, as will be more fully described hereinafter. A rack 12a, provided with a plurality of teeth 12b, is operatively connected to a typewriter carriage 12 (only partially shown), said rack meshing with the teeth of a pinion 13 supported on a rotatable shaft 15. i I

A ratchet wheel 14 providedwith gear teeth 14a is also carried by the shaft 15. A locking pawl 6a disposed adjacent the ratchet wheel 14 and adapted to engage'the teeth 14a serves as the forward end of a locking lever 6 which rocks about a pivot bolt or shaft 16. The line spacing lever 8 is constructed in the form of a bell crank and is provided with an arm 8a supporting a line-spacing pawl 9. A tension spring 10 carried by the carriage. 12 has one end fastened to the arm 8a to normally maintain said arm and its associated pawl 9 in its disengaged or inoperative position. A line-spacing ratchet wheel 11 secured to a typewriter platen (not shown) initiates incremental line spacing of a work sheet upon engagement ,of the line-spacing pawl 9 with the teeth of the rachet movementof the carriage is obtained :by means of a carriage advancing ribbon or .tape 17, wounda'oout a grooveddrum 17a, supported on a shaft 17b. A spring 18,??disposed centrally of said drum, is in registry with one. end .of said tape to cause the latter to wind about the drum 17a. Theaboveedescribed advancing mechanism is conventionally employed in typewriters.

In accordance with the present invention, the locking device :for locking the carriage to prevent the return movement of the same during a line spacing operation, is mechanically actuated bya key Z. The key Z is mounted :on:an=arm 61 oscillating about a shaft 62 and constitutiingone of .a plurality of .typewriter keys forming the itypewriterkeyboard (not shown); said key also serving -to.:actuate adoubledhrow contact switch Z1, as best seen in Figure 2. A link 60 is connected at one end to the arm 61 and at its opposite end is secured to one leg 63a lof a right-angle lever 63 which is .pivotally supported on a shaft .64. Theother leg 63b of lever 63 is secured to a pull rod 19 which, in turn, :has its opposite end flexed into a hook ;69..receivable in .an aperture 65, provided in an -actuatoror .controlnlever .20. This last-mentioned lever is supported by an angle bracket 66 and is pivotable About stub shaft 21 mounted on said bracket.

- .Theleft-hand portion of thecontrol lever 20 is slightly flexed and its left end.is.provided with an .extension defining a tripnose 22 actuated by means of .the pull rod 19, Theopposite end of said control lever 20 is sli htly iinclinedandhas its end portion secured .to a substantially upright lever 23 by means of an oblong-shaped pinslot 22a (see Figure 4). The lever 23 is pivotally mounted adjacent its upper end on a shaft 24 supported by a bracketj24a see Figure 3). The uppermost portion of lthelever 1.23 is provided with a lateral stop flange 23a -a dapted to normally abut against the top surface of the ilocking lever 6 pivotedat v16 on the lever 23. The lock- -ing pawl 6a is engageable with the ratchet wheel 14 for *the purpose of locking the carriage 12 to prevent movement thereof. The locking lever 6 is :held in a predeter- -mined position against the stop 23a bymeansof a spring :26 :carried by a bracket 26a, said spring exerting an up- -wardly directed biasing force on the bottom surface of :thelo'cking lever 6 through the intermediary of a pin 25 located above the spring 26. It is to be noted that the .lever 23 uponactuation of the key Z rotates in a clock- :wisedirectionabout theaxis of shaft 24. Figure 1 dis- .tcloses the position of lever 23 .upon depression, of key Z. if .the .key Z is not actuated, then lever 23 remains in "its rest gposition, whereby the locking pawl 6a does not engage the teeth 14a of the ratchet wheel 14. These -aforementioned parts, and more particularly, pawl 6a, serve to 100k the ratchet wheel 14, thereby preventing displacement of the carriage 12 during the time the key Z is held in its depressed position.

The elements described hereinafter are utilized as an automatic control for the line spacing mechanism independent of the manual actuation of the key Z. A vertigcally arranged control or push .rod 28 is carried by a stationary bracket 28a and supports a circumferentially arranged spring 29, disposed between upper limit stop 30a and the-end 28b of the bracket 28a. The upper limit step 301: and a lower limit stop 30 are also supported by said push rod. A cushion lever 31 provided with a slot :310 for receiving the upper end of. said push rod .is mounted at one end thereof and is adjustable along the length ofsaid push rod by means of a set screw 31b per- ,mitting adjustment of the width of said slot. The cushion layer '31 is further provided with an :upwardly extending finger 31a defining a holding edge adapted to abut the bottom of the locking lever 6. The lower or bottom end of the push rod 28 is operatively connected to a rocking lever 33 pivoting about a shaft 331), said bottom end of the push rod being fastened to a cross member slidable in oval-shaped slots 105a provided on said rocking lever with the aid of pin means 106 guided therein. A switch 3-2 is mounted on a leg 107 which is secured to and extending from the cross .member 105, said switch comprising single pole-single throw elements 32a and single pole-double throw elements 3%. The bracket 28a is secured to thetypewriter or office machine frame-(not shown).

Rocking lever 33 is provided at its free end with a finger 33a extending through and guided by a slot 51b formed in a plate member 51, also secured to the machine frame. The finger 33a rests on a shoulder 34!) at the upper end of a holding lever 34 which is pivotally mounted on .ashaft 50a supported by said plate member. At the :loWer end ofthe holding lever 34, there is provided a downwardly extending arm 34a abutting against a stop member 51a extending from the plate member 51, said .arm 34a being .biased in one direction by a spring 50. One end of a spring 52 is attached to the plate 51, while its other .end is secured to the left-hand portion of the control lever 20, so as to pull the latter in the direction of said plate member. This mechanism is used for the continuous and exact incremental spacing of the work sheet to the next desired line when the key Z is depressed. The operationthereof will be more fully described later on.

Referring now to Figure 2, the motor 36 is connected to an AC. power line 37a .by means of a double pole single throw switch 37 and a single pole-double throw switch 38. The motor 36 is operatively connected to the drawband reel 2, carrying the drawband 4 when an electric coil of the magnetic clutch 1 is energized by an electric current '(see Figure 1). A rectifier 39, in circuit with said motor and receiving its current from said AC. power line 37a via transformer 40, supplies D.C. current for the purpose of energizing the electromagnetic clutch 1 and other components constituting the electric circuits, as will be more fully described hereinafter. One terminal of the clutch 1-will be connected to the plus terminal of the rectifier 39 via a switch r when moved to its lower position by means of a main relay R, whereby this switch r engages contact point 204. The main relay 'R operates four switches r r r and r The other terminal of said clutch is connected to the minus terminal of said rectifier via junction 208. One terminal of the relay R is directly connected to the minus. terminal of the rectifier 39 via junction 207, While the other terminal thereof is connected to the positive terminal of said rectifier by means of a rheostat 41, the single pole-single throw switch 32a and switches 42, 43 and 44. The switch 42 is actuated by a correcting space bar; the switch 43 is a limit switch, while the switch 44 is a tabulator switch. A capacitor 45 has one terminal connected to the-plus terminal of the rectifier 39 by means of switches Z1,

32b

42, 43 and 44, the opposite terminal of said capacitor being connected to the minus terminal of said rectifier via switch r when the'relay is deenergized and said switch engages point 201. V

A resistor 46 is connected in series to the capacitor '45 uponclosing ofa'contact switch W1, said contact switch being operated by a key W which also actuates switches z and A resistor 47 will be shunted to the capacitor 45 when theswitch Z1 is moved to its lower position engaging contact point 209, thereby energizing the coil of the relay R, actuating said relay and causing switch r toengagepoint 202. When the relay switchrr engages point 200, it connects one terminal of the coil of the "relay R to the plus terminal of the rectifier 39, thereby closing the circuit through said relay coil. The contact 'xswitch w which is closed upon actuation of the key W is adapted to complete a circuit through magnet 48; which circuit is supplied from the rectifier 39 when theswitch r, is engaging point 205. The magnet 48 serves to unlock the keyboard of the typewriter when the main circuit breaker switch 37 and switch 49 are closed. 7 Upon opening of the switch 49, the keyboard is locked, unless the switch W2 is closed. A

The switch 32 including switching elements 32a and 32b is schematically illustrated in Figure 2. The mechanism placing the ratchet wheel 14 in registry with the switch 32 is schematically illustrated in Figure 2. This mechanism includes the locking lever 6 and the push rod 28 with the cushion lever 31 mounted thereon. The line spacing operation is controlled by the line spacing lever 8 which, upon energization of the magnetic clutch 1, is actuated via the drawband 4, said drawband 4 being instantaneously tensioned under the action transmitted by said clutch. The line spacing pawl 9 engages the teeth of ratchet wheel 11, causing rotation of said wheel. The drawband 4 is also adapted to exert a force pulling the carriage 12. This movement can be retarded by the inertia of said carriage when at rest, i.e., when the line spacing operation is followed by a carriage return step If the line spacing operation shall take place without carriage return, the locking lever 6 locks the carriage 12 when the pawl 6a engages the ratchet wheel 14, thereby preventing any movement of the gear 13 and its associate rack 12a in registry with the carriage 12.

Line spacing without carriage return The actuation of the locking means for preventing motion of the carriage 12 and the energization of the relay R are initiated by the key Z. Upon depression of said key Z, its motion is transmitted by the pull rod 19 to the pivotally mounted control lever 20, thereby rocking the upright lever 23 about the pivot shaft 24 in a clockwise direction, the bottom portion of the lever 23 moving in the direction of the arrow 23b. As a result of this pivotal movement of the lever 23 about theshaft 24 in a clockwise direction, the locking lever 6 is moved in the direction of the wheel 14, whereby the locking pawl 6a is brought into contact with the teeth 14a of said wheel. At the same time, the spring 26 holds the pin 25 in its resting position, so that the left end of the locking lever 6 abuts the stop flange 23a. During the last phase of this locking step, the trip nose 22 releases the holding lever 34 which previously was locked, as its arm 34a was abutting the stop 51a under the action of the spring member 50. Upon release of the holding lever 34, the rocking lever 33 is also released since its finger 33a no longer maintains its abutting relationship with the shoulder 34b provided on said holding lever. As a result of this, the push rod 28 moves upwardly under the action of the spring '29, said movement being limited by the stop 30. Thus,

the cushion lever 31 is brought into a new position directly below the locking lever 6. The single pole switchelement 32a, disposed adjacent the lower end of the push rod 28, is adjusted and positioned in such a manner, that said switch 3201 does not close until the cushion lever 31 has arrived in exactly the position described above. The position of the double-throw switch 32b has now changed, whereby said switch engages contact point 210, see Figure 2. Furthermore, the holding surface or upper edge 31a ofthe cushion lever 31 contacts the lower surface of the locking lever 6 in such a manner, that the locking pawl 6a engages one of the teeth 14a of ratchet wheel 14 to maintain the carriage in its locked position even if thekey Z is subsequently released.

The importance of the operation and function of the cushion lever 31 can best be appreciated if it is considered that said holding surface prevents a counterclockwise pivotal movement of the lever 23 about the shaft 24. This pivotal movement would normally occur upon release of. the key Z asv a result of the pulling force exerted. :by the: return spring '52 acting on the control leverf20. Prior to depression of the key Z, i.e., when the switch z contacts point 211, the capacitor is connected directly across the rectifier 39 to permit charging of said capacitor. Thus, upon depression of key Z, the contact switchz moves down to a new position 209 and connects said capacitorto line junction 63, as illustrated in Figure 2. l

' When the contact 32a is closed, due to the lifting of the push rod 28, as previously described, the capacitor 45 will be shunted to the coil of the relay R. Consequently,"thecoil of the relay R and the shunted capacitor 45' are connected to the rectifier 39 via the rheostat 41 and switches 32a, '42, 43 and 44. Thus, the coil of therelay' R, which is fed directly by the rectifier, will be enefgized to activate switches r r r;, and r Closing of the switch r ,,|by moving it into position 204, connects the magnetic clutch 1 to the rectifier 39 and energizes said clutch. Due to the energization of the clutch 1, torque will be transmitted to the drum 2, cansing tens ioning of the. drawband 4 and, thereby, engagement of the line spacing pawl 9 with its associated ratchet wheel 11, thus carrying out a line spacing operation on a work sheet. After completion of the line spacing step, the pulling forceexerted by said drawband and transmitted to the carriage 12 by an elbow 5b is increased, due to the torque build-up of said clutch. This pulling force is transmitted to the teeth 14a of the ratchet wheel 14 by means 'of rack 12a and pinion 13, turning the lockinglever 6 about its fulcrum or pivot 16 in 'a' counterclockwise direction, overcoming the force of the spring 26.

1 As a'result of this, the push rod 28 is moved downwardly, whereupon the switch element 32a of the switch 32 iopen's, deenergizing the coil of the relay R and cansingfthe' clutch 1 to disengage the drum 2 from the driving motor 36. The relay switch r;, then assumes its initial contact position 203; Since'the clutch 1 is now disengaged, the pulling force previously exerted on the line spacing lever 8 through the intermediary of drawband'4 is 'entirely removed and the lever 8 will return to its initial position under the action of the spirng 10. If the key Z would be released prior to the operational steps-described above, the spring 52 would pull the control, lever 20 into its neutral or rest position and the locking lever 6 would return to its original position against the action of the spring 26, while the clutch 1 would become disengaged. Thus, the upright lever 23 would withdraw the pawl 6a of locking lever 6 from the previously engaged teeth of ratchet wheel 14. Such disengaging movement could not be prevented by the cushion lever 31.

However, if the key Z is continuously held in its depressed position, one line spacing step will be followed byanother, as the control lever 20 will not be able to return to its rest position under the action of the spring 52. Thus, control lever 20 will remain in its carriage locking position, i.e., will be biased in the direction of the arrow 23b. Therefore, after the completion of one line spacing operation, the locking lever 6 will disengage from the ratchetwheel 14, opening contact switch 32a due to a lowering of push rod 28. Consequently, the relay R will be deenergized, as described in the foregoing. However, prior to the deenergization of said relay R, the capacitor 45 has been discharged via the closed switch r which is in position 202, the resistor 47 and the closed contact z to dissipate the charge on the capacitor. If, now, the pressure acting on the locking lever 6 is decreased by releasing the tension on the drawband 4,line'spacing lever 8 and the rack 12a, the push rod 28 will be moved upwardly under the action of spring 29, to reclose the switch 32a. This operation 99ers new? h s relw r a he 1m; Bi un to return toits initialpositi on under'the action of spring 10, so as. tofbe *in its .proper positi'on forra subsequent line spacing step. I In order 'to obtain an accurate and properly functioning .line spacing operation; the reclosing step of the switch 32a must b'ejd'elayed long enough to enablejthe line spacing levers'to return to its initial position and to initiate another line'spacingoperation.

' This required time-delayin the function 'of:.the irelay R is, obtained by the resistor .41. During thefirst line spacing step, thecapacitor '45 "is completely charged when shunted across the relay R. Whenthe switch 32a is now reclosed, the capacitor 45 .will be partially dischargedand the rheostat 41 together "with 'thecapacitor ;45'form a time-delay RC member. 'Asaresu'lt'of this, the subsequent energization of relay Ris' delayed for a predetermined 'rncrement'of time, said delay being of such magnitude that the spring '10 hasp'suflicient'time to return the line spacinglever '8 to its initial position,'thus pemrittingthe next line spacing :operation. Consequently, one'properly timed line spacing cycle is followed by another as long as the key ,Z 'is held in its depressed position. By. changing the values of the time delay RC member, the number of line spacingsteps per unit of time may be increased or decreased as desired. Such change can be obtained, tor example, by connecting additional resistancestothe rheostat .41 'or by'varying said "rheostat.

' The carriage return The essential circuit components tor performing the line spacing operation Without carriagereturn movement are also employed tor carrying 011M143. line spacing .operation with subsequent carriage return. Thus, upon depression ofthe key W, the contact switches Z1, w; and w, are closed. However, the locking device ,for the carriage 12, including .the locking lever 6 and ratchet wheel 14arenot "in their locking positions, as xdescribed above, since the key W does not actuate the pull rod.19 and its associated .members. The capacitor -45, which was in charged condition prior'to. depression of the key W and connectedin the circuit of rectifier 39

Mia components'r Z

32b, 42,43 and, now discharges via the contact z in position 209, and the coil of the relay R. ASJB. .result thereof, therelay coil is. energized and aetuates switches r x 1 and r said switches assuming a new position. More specifically, the relay switch r assumes the position 200,.thereby maintaining said relay continually energized via elements r 32b, 42,- 43 and 44, evenifthe capacitor 45 is discharged. The relay switch r then also closed, i.e., in position 204, connects thesmagnetic clutch ..1 directly to the rectifier 39,1whereb'y current is fed toclutch 1 until the limit switch 43.0pens to interrupt the current supply to the coil ..of the .relay R, thus deenergizing the latter.

'Upon energization of clutch. 1, thewline spacing operation will be carried out by means ofthe line spacing pawl'9 engaging the ratchet wheel-11. Inaddition, carriage return is obtained, .as the ratchet wheel 141s not inits locked position. However, it may be that the key W is'st-il l'depressed whenthe limit switch '43 has opened and reclosed after an immediate return of the carriage. Sue-h immediate reclosing could cause recharging of the capacitor -45.- To prevent such premature charging," the resistor 47- is shunted to the capacitor 45 as long as the relay .R isener'gized. Thus, the capacitor 45 will completelydi-seharge during energizationof the relay Rand the high resistancex46prevents recharging :of the capacitor. Upon release of the key W, the contact switch Z1 resumes its initial position 211 and -againjconnects the capacitor 45 to the rectifier 39, so as to charge the capaciton- The releasewof the. key W simultaneously causes. .the ,switchw to .open ..and vto disconnect the capacitor 45 from the relay R.

' Locking The magnet acts on akxrown-ball locking device (not shownliadapted :to "lock 'the typewriter keyboard including-the keys W andZ. Upon closing ofthesingle throw switch .37, "having switching elements 37b and 37c, the magnet unlocks "thefkeyboard to "put the typewriter in operation. The contact switch n, of the relay R and the contact switch "49 of the margin set key are adapted to openthe circuit of the magnet 48, so that the "keyboard :can belocked. "iUpon actuation of the margin set key, the contact 49"cazn be reclosed, thus unlocking the keyboard. When the contact 49 is opened, aline spacing operation with a subsequent carriage return can be carried out, because the key W acts on the contact w WhiCh"iS below the key Z. This contact W2 closes the circuitof the magnet 48 to unlock the keyboard. Ac: cording-1y, the locking of the keyboard is released upon aslight pressure .on the key W. When the relay R is energized, the contact r moves to the position 206 and thereby opens the circuit of the magnet 48. Thus, the keyboard "becomes locked during the carriage return. Thelinespacing and the carriage return steps can be interrupted by actuation of the

switches

42, 43 or 44, whichare inserted in series in the control circuit for the relay. R. Such interruption may be carried out-during tabulation or upon depressing the back-spacer.

'Thus, the same relay R is used for actuating the line spacing step with or without subsequent carriage return. For line spacing without subsequent carriage return, .the circuit of the relay R will be closed by the contact 32a of the switch 32, when released by the pull rod 28.

When the line spacing step is carried out by depressing the key W,.the contacts W1 and W2 close, while the locking device remains in its rest position. The capacitor 45 discharges, as described in the foregoing, through the coil of'the relay R. The relay R is energized and remains energized via the holding switch r This self-holding function of the relay R is very important for the line spacing step with subsequent carriage return. However, the self-holding means must be rendered ineffective for the line spacing. step without subsequent carriage return, because an active self-holding means would prevent opening of the contact 32a carried out by means of the push rod 28. Therefore, the contact 32b is provided to close the circuit for the self-holding means in either of its two resting

positions

210 or 212. However, shortly after the mechanism for the line spacing step is disconnectedby the contact 32a of the switch 32, the contact 32b changes its position from 212 to 210 or versa, thereby rendering the controlling energizing circuit for the relay R entirely deenergized for a short period of time and causing opening of the relay R, as the latter has a very short release time.

1. In a power-operated typewriter and the like, a displaceab'le carriage, a platen rotatably mounted on said carriage, line spacing means connected to said platen for rotating said platen in predetermined increments, drive means communicating withsaid line spacing means and saidcarriage and adapted to initiate at least one line spacing operation on a work sheet, locking means operatively connected to said carriage and adapted to lock said carriage to prevent movement thereof, first key means in registry with said carriage locking means for actuating the latter, control means actuated by said first key means for operating said drive means including an electrical power source, a relay, first switch means operated-by said first key means to connect said relay to said power source, and second switch means actuated by said relay for connecting said drive means to said power source, second key means for actuating said control means independently of said first key means, whereby said drive means performs a line spacing operation on said work sheet followed by a carriage displacement, and means communicating with said locking means and said "first switch means, said communicating means being acted upon by said drive means via said locking means for operating said first switch means upon completion of a line spacing operation, said control means further including time delay means operatively connected to said relay to prevent premature energization thereof and to permit said line spacing means to return to a predetermined initial position in readiness for a subsequent line spacing operation.

2. A power-operated typewriter and the like according to claim 1, wherein said communicating means include a push rod, a biasing spring carried by said rod, a cushion lever supported at one end of said rod and adapted to contact said locking means, said biasing spring moving said push rod in one direction to close said first switch means when said drive means is inoperative.

3. A power-operated typewriter and the like, according to claim 2, wherein said communicating means further include a rocking lever connected to the other end of said push rod, said rocking lever being provided with an extension defining a finger, a holding lever pivotably connected to said first key means and in one position abutting said finger, whereby actuation of said first key means pivoting said holding lever will release said finger to permit displacement of said push rod for intermittent actuation of said first switch means.

4. In a power-operated typewriter and the like, a displaceable carriage, a platen rotatably mounted on said carriage, line spacing means connected to said platen for rotating said platen in predetermined increments, drive means communicating with said line spacing means and said carriage and adapted to initiate at least one line spacing operation on a work sheet, locking means operatively connected to said carriage and adapted to lock said carriage to prevent movement thereof, first key means in registry with said carriage locking means for actuating the latter, control means actuated by said first key means for operating said drive means including an electrical power source, a relay, first switch means operated by said first key means to connect said relay to said power source, and second switch means actuated by said relay for connecting said drive means to said power source, and second key means for actuating said control means inde pendently of said first key means, said control means further includin a capacitor supplying electric energy to said relay upon actuation of said second key means, said energizing relay connecting said drive means to said power source via the intermediary of said second switch means, said locking means remaining inoperative during actuation of said second key means, whereby said drive means causes a line spacing operation which is followed by a carriage displacement.

'5. A power-operated typewriter and the like according to claim 4, wherein said control means further includes a resistor which is shunted to said capacitor during energization of said relay.

6. A device for line spacing typewriters and similar ofiice machines provided with a displaceable carriage comprising driving means in registry with said carriage for driving the latter, relay means in an electric circuit with and controlling said driving means, first key means for initially energizing said relay means, a line spacing mechanism actuated by said driving means and communicating with said carriage, a ratchet wheel associated with said carriage, a locking lever engageable with said ratchet wheel in one position to lock said carriage, a first switch actuated by said first key means and controlling said relay means, a push rod for engaging said locking lever and said first switch, a holding device operatively connected to said push rod and adapted to release said push rod for engaging movement thereof upon actuation of said first key means, second switch means actuated by said relay means and connecting said drive means to a power source and a second key controlling said relay means independently of said push rod and said locking lever.

7. The device according to claim 6, including a capacitor adapted to be connected in circuit with said relay means by said first key means, and a resistor adapted to be connected in series with said capacitor and said relay means upon actuation of said first key means.

8. The device according to claim 7, wherein the magnitude of the resistance in said circuit is variable so that the product of the capacitance of said capacitor and the resistance of said resistor can be altered, thereby defining an adjustable time delay component.

9. The device according to claim 6, wherein a plurality of switches are connected in series to and control said relay means, said switches including a limit switch and a tabulator switch.

10. The device according to claim 6, including magnet means -for locking the keyboard of said typewriter upon depression of said second key, whereby said keyboard is locked during displacement of said carriage.

11. The device according to claim 6, wherein said holding device comprises a pivotal holding lever responsive to actuation of said first key means, a control lever abutting one arm of said holding lever and a rocking lever held in a predetermined position by said holding lever and released therefrom upon actuation of said first key means.

12. The device according to claim 11, wherein said push rod is carried by said rocking lever and is adapted to control engagement of said locking lever with said ratchet wheel upon actuation of said first key means.

13. The device according to claim 11, including a cushion lever supported at one end of said push rod and engageable in one position with said locking lever.

14. The device according to claim 6, including spring means disposed adjacent said locking lever and influencing the engagement of said locking lever with said ratchet wheel.

15. The device according to claim 6, including biasing means carried by said push rod urging said rod into engagement with said locking lever upon actuation of said first key means.

References Cited in the file of this patent UNITED STATES PATENTS 1,143,404 Kennedy June 15, 1915 1,509,228 Carino Sept. 23, 1924 2,104,007 Bower Jan. 4, 1938 2,262,676 Helmond Nov. 11, 1941