US3021937A - Selective interlock mechanism - Google Patents

Description

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BY [4% M ATTORNEY Feb. 20, 1962 R. E. SEYMOUR 3,021,937

SELECTIVE INTERLOCK MECHANISM Filed April 12, 1960 2 Sheets-Sheet 2 CAR. R57? RAYMOND 1 arm/om BY ZJM/AMMQ A 77' OR/VE Y United States This invention relates generally to locking devices for mechanically controlled machines suchas a typewriter, bookkeeper or the like and, more particularly, to a selective interlock device associated with the control members of such apparatus for selectively disabling various combinations or groups of said control members at different stages of the machine's operation. I

. The invention is disclosed herein in an embodiment adapted for use with the keyboard: of an electric typewriter, of'well known design, but it of course should be understood that the invention may be adapted for use with keyboards of machines other than typewriters or in fact to any mechanical apparatus having control members. equivalent to the key. levers of a typewriter or the like.

The invention, in the embodiment herein disclosed, is intended to prevent the operator of a typewriter from making certain kinds of errors in typing operations wherein the machine is being utilized for producing formatted copy. For example, when the typewriter is utilized for preparing certain business forms a predetermined area of a line of typing might call for only numerical data, another area of the line mightcall for only alphabetic data, etc. The format may also require that each line of typing contain an over all line area of predetermined extent in which case the initiation of a carriage return operation acters as code symbols and the typing of a code symbol at a predetermined carriage escapement position in a given line of typing, in which case the typing of any other character at the predetermined carriage escapement position would likewise constitute a typing error.

'The device according to the invention includes a plurality of lock-up slides, one for performing each separate lock-up function. Accordingly, with the device set up for performing the interlock functions of the sort abovementioned by way of example, one of the slides would be associated with only the numeric keys so as to be brought into operation to prevent operation of the numeric key, in all of the line area wherein numeric information or data is not called for; another slide would be similarly associated with all alphabetic keys except those employed for code symbols, to prevent operation of these alphabetic keys in those areas o-f'the line wherein alphabetic data was not called for; another slide would be associated with the carriage return key so as to prevent operation of the carriage return key until' a line of the prescribed extent had been completed; and another slide would be associated with the code symbol keys so as to permit operation of only these keys at the prescribed carriage escapement position of the line area.

Associated with each of the locking slides is an electromagnetic actuator for controlling the shifting of its associated slide. The actuators may, in turn, be controlled by any appropriate circuit closing means, not shown herein, which operates to complete energizing circuits to the actuators in accordance with the escapement position of the carriage of the machine. The design of the locking slides and associated parts is such as to permit close spacing between the slides thereby enabling a large number of such slides to be included within the normally crowded area provided by a typical machine keyboard and, furtheratent more, to permit wide flexibility and ease in adapting the device to meet the requirements of diflerent formats. An important feature of the device resides in the nature of the means mounted on such slides for limiting or blocking the movement of associated key levers. Said last mene tioned means comprise interponent members made of flexible material,.which members normally assume a posithe selective interlocking of a plurality of groups of mechanical members such as the key levers of keyboard operated apparatus.

It is a further object of this invention to provide an interlock device which is easily and readily adaptable for performing a wide variety of different interlocking. functions.

It is a further object of the invention to provide a mechanical interlock device for a plurality of groups of control members which is incapable of jamming and in which the effectiveness of the device-is not dependent, upon restortation of a control member to its inactive position before the associated locking means for maintaining said control member'in inactive position is actuated.

' Further objects of the invention, together with features contributing thereto and advantages resulting therefrom, will be apparent from. the following description when read in conjunction with the drawings wherein:

FIG. 1 is a sectional view from the left hand side through a portion of a typewriting apparatus showing the interlocking device in accordance with the present invention associated with the keyboard thereof.

FIG. 2 is a plan view of the device with portions of the keyboard broken away.

- FIG. 3 is a fragmentary view of the device in front machine containing the individual key buttons 11 in the usual four-bank arrangement, each key button being mounted on the upright arm portion of a related key lever 12. In 'the instant machine, for reasons which willhereinafter become apparent, all keys which are to be" under control of the selective interlock mechanism are provided with a flat limit surface 13 at their forward extremity, said limit surfaces for all keys aligning with one another in a horizontal plane extending across the front of the keyboard. In order to achieve this result it will be noted that the key levers 12 associated with the upper three banks of key buttons 11 are formed with arms extending forwardly of their upright stern portions, the length of said forward extensions being dependent upon the respective banks of keys to which the key levers are related.

To briefly describe the key action, each key lever is pivoted on a common pivot rod 14 and carries a stud 15 which engages a bell crank 16. The rearmost arm of bell crank 16 pivotally supports a pawl 17 which engages an car 18 formed on a pivoted arm 19 which hasa pin and slot connection with a finger-like actuator mem-Q ber 21. The arm 19 and actuator 21 are pivoted to a power arm member 22 and are under tension of a spring 23. The power arm also supports an eccentric roller 24 which in its normal inactivated position, as shown in FIG. 1, is disengaged from the main power roll 25 which is driven in a clockwise direction and extends across the width of the machine providing a source of driving power to each of the several key actions; Depression of one of the keys 11 and the associated key lever 12 operates through bell crank 16 to elevate pawl 17, rocking arm 19 clockwise against tension of spring 23 and rocking actuator 21 counterclockwise into engagement with a cutaway shoulder 26 formed on the eccentric 24. This action causes the eccentric to rotatae a sufiicient distance so as to come into driving contact with the power roll 25 whereupon the eccentric action through rotation of the roller 24 causes the power arm 22 to rock clockwise about pivot 27. A rearwardly extending arm 28 secured to the power arm 22 carries a camming roller 29 hearing on the camming shoulder of a lever 31 pivoted at 32 and connected by pull rod 33 to the type lever 34 which in turn is pivoted at 35. Accordingly, it will be seen that manual depression of one of the keys 11 will trip or set in motion the associated power mechanism to cause a rapid rise and fall of the power arm extension 28 and result in a corresponding rocking of the type lever 34 whereupon the type head 36 strikes the platen 37 and returns to the position shown at the completion of a cycle of the typing action. It willbe noted that all of the power driven parts of the mechanism just described operate through one full cycle of movement whereupon they restore to the position as shown, and this results even though the key 11 operated to trip off the power action is held depressed, either inadvertently or otherwise, and is not released before completion of a cycle of the power driven mechanism. l

It will of course be understood that the power driven mechanism also operates, through carriage escapement mechanism not shown herein but of any conventional type, to cause the escapement of the carriage supporting the platen 37 to position the sheet or form being typed in preparation for the next cycle of typing action. Carriage escapement movement occurs immediately after the type lever 34 strikes the platen and during that portion of the cycle that the type lever is returning to its restored position. Itwill be apparent that in view of the high operating speed of the power drive roll and consequent short cycle time for the power driven mechanism, a complete cycle of typing action, including carriage escapement, may easily be accomplished before the activated key 11 has been fully released by the operator of the machine.

In FIG. 1 is also shown a conventional form of keyboard lock-up mechanism which includes a locking pawl 37 piovtally secured to each key lever 12 and yieldably tensioned by spring 38 against a limit stud 39 formed on each key lever. A lock-up bail 41 extending across the full width of the keyboard underlies the tail portion of said pawls and is mounted so as to be rockable into and out of blocking relation to the lower edge of said pawls 37, said bail being actuated to assume its blocking position whenever it desired that the full keyboard be locked up. The pawls are mounted so as to yield against the tension of springs 38 in order to permit the bail 41 to imove into blocking position even though one of the key levers 12 may be depressed at the time the bail 41 is actuated. In such an event the pawl will snap back into its normal position when the depressed key is released thereby preventing further depression of that particular key or any other key of the full keyboard. Without this yieldable feature of the pawl mechanism, a key lever in depressed or operated position at the time the ball 41 is actuated would prevent the bail from assuming its blocking position and could possibly result in a jamming of the keyboard mechanism.

- 55 secured to the side frames of the machine.

The selective lock-up mechanism in accordance with the present invention includes a plurality of lock- up slides 51, 52, 53, 54 which extend across the front of the keyboard beneath the key levers 12, each of said slides being disposed in opposed relation to the horizontal limit surface 13 formed on each key lever 12 as aforesaid. The slides are supported at each end thereof by comb brackets Depending from the lower edge of each slide is a bifurcated arm 56, and formed off the upper edge of each slide are a series of upright lugs 57 which are spaced apart the same distance as the spacing of adjacent key levers 12.

A spring 58 stretched between each slide and the left hand support bracket 55 urges-the respective slide to its leftmost limit position, in which position the lugs 57 do notalign with the key levers 12 but rather align with a point substantially halfway between adjacent key levers.

Individually associated with the slides 51 to 54 are electro-magnetic actuators 61 through 64, respectively, said actuators being mounted on a support plate 65 extending across the width of the keyboard and suitably secured to the side frames of the machine. The armature 66 of each actuator engages the bifurcated arm 56 of its respective slide whereupon energization of the actuator causes a shifting of the associated slide to the right so as to assume a position wherein the upright lugs 57 align directly with the key levers =12.

The upright lugs 57 serve as a means for mounting interponent members 67 in various arrangements with respect to the key levers, the interponent members being in the form of tightly wound coil springs of sufiicient rigidity so as to maintain an upright stable position when mounted on one of the lugs 57. The interponent springs 67 have an outside diameter which preferably is at least equal to the thickness of a key lever 12, but which is considerably less than the space between adjacent key lvers. The inside diameter of each spring 67 is of such dimension as to provide a snug fit with the upstanding supporting lugs 57. The longitudinal dimension of each spring is such as to permit the upper extremity of the spring to just clear beneath the limit surface 13 of the associated key lever when the lock-up slide upon which is mounted is moved to the right to its effective lock-up position at a time when the respective key lever is in its upper normal unoperated position. Since the springs are tightly wound they are not capable of being further compressed so that when underlying the key levers 12 they provide a positive blocking resistance to key lever movement thereby efiec tively locking up the associated key levers. Although the springs 67 are sufficiently stable to provide a positive resistance to longitudinal thrust, such as by manual depression of one of the keys 1 1, they however are capable of yielding under the influence of horizontal thrust, and this action can thus be seen in FIG. 4 which shows one of the springs 67 being bent out of its normal upright stable position. FIG. 4 shows two of the key levers 12 and interponent springs 67 associated therewith which are carried by the lock-up slide 51, the parts being shown in a condition wherein the lock up slide 51 has been moved into locking position at a time when one of the key levers 12 is still held in its operated, depressed position. This occurrence could arise at any time when the format control with respect to a selected group of keys changes from the unlock to lock-up condition, and it will be noted that since these springs 67 are able to bend in a lateral direction, the holding of one of the key levers 12 depressed at the time that the slide moves into lock-up position does not prevent the slide from assuming the lock-up position. Accordingly, all the other key levers !12 associated with the said slide will be effectively locked up by the respective interponent springs 67, and as soon as the key lever, which was in depressed position at the time the slide was actuated, is released, the associated interponent spring 67 will then restore to its normal upright condition to prevent further operation of that same key lever. If the interponents 67 were not capable of yielding in a lateral direction in the manner just described, a depressed key lever 12 could prevent a slide from moving into its lockup position to thereby prevent any of the key levers associated with said slide from being locked up until the depressed key lever is restored, thus defeating the purpose of the selective lock-up mechanism.

Asan example of one application of the invention to a particular use, we might assume that a typewriter is to be used for preparing formatted material wherein the format calls for a line with exactly eighty letter space positions; wherein the first ten letter space positions areto contain only numeric data; wherein the next twenty positions are to contain only alphabetic data; wherein the next 49 carriage escapement positions may contain both alphabetic andnumeric data; and'wherein' the eightieth carriage escapement position is to contain a code symbol consisting of any one of the five vowels a, e, i, 0, or n. In setting up the device for this particular format, one of the slides such as lock-up slide 51 would be assigned for locking up alphabetic key levers and thereby would be provided with interponent springs 67 in position to block each of the alphabetic keys other than the vowel keys, a, e i, 0, or u. Lock-up slide 52 would be provided with interponent springs 67 at the proper positions for cooperating with only the vowel keys, a, e, i, o, and u. Slide '53 would be provided with interponents 67 at positions cooperating with only the ten numeric keys of the keyboard, while slide 54 would be provided with a single interponent '67 in position to cooperate with the carriage return key of the keyboard. With the device set up in this manner the circuit closing means for actuators 61 through 64 would be conditioned so as to complete circuits to actuators 61, 62, and 64 throughout the first ten carriage escapement positions thereby actuating lock-up slides 51, 52 and 54 to permit operation of only the numeric keys throughout the first ten letter space positions. The circuit closing means would then be conditioned to interrupt the circuit to actuators 61, 62 and to complete a circuit to actuator 63 as the carriage escapes to the eleventh letter space position, maintaining this circuit condition throughout the next twenty letter space positions thereby to permit operation only of all the alphabetic keys of the machine. The circuit closing means would then further be conditioned to open the circuit to actuator 63 as the carriage escapes to the 31st space position maintaining this condition throughout the next forty-nine space positions and thereby permitting the operation of either the numeric or alphabetic keys of the machine.

As the form is escaped by the carriage into the eightieth letter space position, the control circuit would be conditioned to reestablish circuits through actuators 61 and 63, leaving only actuator 62 deenergized, thereby permitting operating of only one of the five vowel or code symbol keys at the eightieth line space position. As the carriage moves into the eighty-first line space position, the circuit closing means would be conditioned to reestablish the circuit through actuator 62 and to open the circuit for actuator 64, which latter actuator would be the only one deenergized when the carriage in on the eighty-first line space position thereby permitting the operation of only the carriage return key at this carriage escapement position. For all further carriage positions within the capacity of the machine actuators 61 through 63 would remain energized to prevent the operation of any character key thereby assuring that the typing line contain no more than eighty characters.

From the foregoing, it will be apparent that the instant invention, in an embodiment such as herein disclosed for use with the keyboard of a typewriter or the like. will greatly reduce the possibility of operator error in carrying out a formatted typing operation by restricting the operator to the use of only a particular key or particular group of keys at any given letter space position and locking up all other keys of the keyboard corresponding to machine functions or data the nature of which is not permitted at the particular letter space position by the format being followed. It will also be apparent that the use of tightly wound coil springs-67 as blocking interponents, supported on the slide members and having the characteristics above described, represents a highly desirable feature in mechanism of this type since, in addition to providing the necessary yield for the mechanism, the arrangement permits the device to be easily and quickly setup in accordance with a. wide range of format requirements.

While there is shown and described what is considered to be a preferred embodiment of the invention, it is ob vious that many changes of form could be made without departing from the spirit of the invention, and it is intended, therefore-,that the-invention be not limited to the exact form shownanddescribed nor to any thing less than the whole of the invention as hereinbefore set forth and hereinafter claimed.

What is claimed as new, and desired to be secured by Letters Patent is:

1. In apparatus of the class described having a plurality of control members arranged in parallel spaced apart relation to each other and each movable in the same direction from inoperative to operative position within its respective plane, means for locking up selected ones of said control members, said means including a lock-up member longitudinally disposed adjacent to and along a line intercepting the plane of each of said control members, said lock-upmember being shiftable longitudinally into and out of lock-up position, and interponent means mounted on said lock-up member and positionable in the plane of a selected control member by the shifting of said lock-up member into lock-up position to limit the 0perative movement of the selected control member, said interponent means being longitudinally disposed between said lock-up member and a control member and formed to positively resist thrust applied thereto in a longitudinal direction and to yield to thrust applied thereto in a lateral direction.

2. In apparatus of the class described having a plurality of control members arranged in parallel spaced apart relation to each other and each movable in the same direction from inoperative to operative position within its respective plane, means for interlocking selected groups of said control members, said means including a plurality of lock-up members each longitudinally disposed adjacent to and along a line intercepting the plane of each of said control members, said members being shiftable longitudinally into and out of lock-up position, and interponent means mounted on each of said lock-up members in position for cooperating with an associated group of control members and positionable in the plane of the control members of an associated group by the shifting of a lock-up member into lockup position to limit the operative movement of said control members, each said interponent means being longitudinally disposed between a lock-up member and a control member and formed to positively resist thrust applied thereto in a longitudinal direction and to yield to thrust applied thereto in a lateral direction.

3. The invention according to claim 2 including means for selectively shifting said lock-up members into and out of lock-up position.

4. The invention according to claim 1 wherein said interponent means are detachably mounted on said lockup member.

5. The invention according to claim 1 wherein said interponent means comprise tightly wound coil spring members.

6. The invention according to claim 1, wherein said interponent means comprise tightly wound coil spring members and wherein said lock-up member is formed with a series of projections spaced apart equally to the lateral spacing of said control members, each of said projections being shaped to provide a mounting for one of said coil spring members.

7. In apparatus of the character described having a keyboard including a plurality of key levers, keyboard lockup means including a shiftable lock-up member underlying the key levers of said keyboard and provided with interponents for blocking the movement of associated key levers when said member is shifted to an effective lock-up position, said interponents being longitudinally disposed between said member and associated key levers and formed of a material and shape to provide positive resistance in a longitudinal direction to key lever movement and yield'able resistance in a lateral direction to the shifting movement of said lock-up member.

8. The invention according to claim 7, wherein said lock-up means comprises a plurality of lock-up members and including actuator means for selectively shifting said members into effectivelock up position.

11. The invention according to claim 10, wherein said lock-up member is formed with a series of projections spaced apart equally to the lateral spacing of said key levers and formed to fit the bore of said springs to pro- 10 vide a detachable mounting support for said coil springs.

References Cited in the file of this patent UNITED STATES PATENTS 1:169334 Harding July 1, 1930 2,320,637 Modigliani June I, 1943 2,505,703

Chisholm May 9, I950

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