US2255329A - Signaling device for typewriters - Google Patents

Description

Sept-9,1941. J. Y. PA-YT'QN 2 255,

SIGNALING DEVICE FOR TYPEWRITERS Filed Dec. 6, 1939 -/7 -INDVENTOR ii/g5; XEu/ce mV/Zwroa/ mm ,W

ATTORNEY Patented Sept. 9, 1941 SIGNALING DEVICE FOR TYPEWRITERS James Y. Payton, Los Angeles, Calif., assignor of one-fifth to Louis E. Payton, Los Angeles,

Calif.

Application December 6, 1939, Serial No. 307,790

6 Claims.

This invention relates to signaling devices for typewriters, of the general character embodied in my U. S. Patent No. 2,168,070, issued August 1, 1939, wherein mechanism functions automatically to signal to the typist the proximity of the typing to the hidden lower edge of the sheet being typed.

An object of the present invention is to provide a signaling device for typewriters which, through the medium of a novel arrangement and functional relationship of elements possesses, among many advantages, the following:

1. Positively prevents activation of the signal during retrograde movement of the platen which is necessary to enable errors in the typed matter to be corrected.

2. Insures suflicient storing of spring energy during advancing movement of platen, for activation of the signal, and irrespective of a relatively small amount of platen movement when using short sheets of paper.

3. Reduces to a negligible minimum such friction as might jam or otherwise adversely affect a releasable operative connection established between the signal actuator and the actuating spring therefor to effect winding of the spring, so as to insure that the energy stored in the spring during advancing movement of the platen will be released by positive disruption of the operative connection when the bottom edge of the sheet being typed reaches a predetermined position relative to the platen.

4. Obviates a defective or incomplete operative connection between the signal actuator and the actuating spring therefor, which might result in premature activation of the signal during the typing operation.

5. Simplifies the paper controlled means for establishing and releasing the operative connection between the signal actuator and its actuating spring, by reducing the number of parts and modifying other parts in a manner to prevent binding or holding of such means against the release of the operative connection when the sheet being typed reaches a predeterminedposition relative to the platen.

With this and other objects in view, the invention resides in the combinations and arrangements of elements as set forth in the following specification and particularly pointed out in the bbdying this invention, applied to a typewriter platen;

Figure 2 is a plan view of the signaling device applied to the platen;

Figures 3 and 4 are transverse sectional views taken, respectively, on the lines 3--3 and 4-4 of Figure 1;

Figure 5 is a transverse sectional view taken on the line 5-5 of Figure 1 and illustrating the position of the signaling device during the typing operation;

Figure 6 is a view similar to Figure 5 but showing the released position of the device;

Figure 7 is a transverse sectional view taken on the line 1-4 of Figure 1;

Figure 8 is a perspective view of a striker embodied in the invention;

Figure 9 is a perspective view of the striker actuating cam.

Referring specifically to the drawing, the platen P of a typewriter is fixed to the usual operating shaft l0 journaled in bearings Ii on the typewriter carriage (not shown) and differs from a conventional platen by being slightly reduced in length from its left end to provide space in which the signaling device is received in a manner not to affect the normal use of the platen.

Fixed in a recess l2 in the left end of the platen is a cup member l3 adapted to receive a portion of the signaling device, the member having an axial opening through which the shaft l0 projects. The shaft has fixed thereto for rotation with the platen, an audible signal B in the form of a bell l4 adapted to be sounded by a striker S. The striker comprises a length of spring wire one end of which has fixed thereto a head it. The other end of the wire is in the form of a short coil I! wound in an annular recess i8 formed in the hub l9 of the bell, so as to be constricted and become locked to the hub when force is exterted upon the striker to rotate same in one direction on the hub, and to be expanded and thus become frictionally free on the hub when force is exerted upon the striker to rotate the latter in the opposite direction on the hub, all for a purpose to be later fully described.

That portion'of the striker S between the head l6 and coil ll provides a spring arm 22 which normally urges the head IS in a plane substantially parallel to the axis of the shaft in, away from the bell Hi to a position clear of the latter.

The striker S, and specifically arm 22 thereof, is adapted to co-act directly with an energy storing and actuating unit U which is controlled by movements of the platen P and by a sheet of paper extended around the platen as in typing. This unit comprises a. ring 23 freely fitting into the member l3 and having an annular groove 24 re celving an undulated spring 25 normally tending to expand into engagement with the internal annular surface of the member l3 with suflicient force to provide a driving connection between the platen and ring by which the latter is caused to normally rotate with the platen.

A flat coil spring 26 is normally expanded within the ring 23 and has its outer end fixed in any suitable manner at 21 to the ring. The inner end of the spring 26 is provided with a hook 26 which co-operates with ratchet teeth 28a to anchor the hook against forward movement around the locked hub 29 but permits such movement of the hook in the opposite direction. The toothed portion of the hub 29 occupies the center of the coil spring and projects from one side of a rotary actuator or disk 36 which is of a diameter to be received in the member 13 alongside the ring 23, and is mounted to freely rotate on the shaft Ill.

The other portion of the hub 29 projects from the opposite side of the disk 30 and has threaded thereon so as to solidly abut a shoulder 3| on the hub, a rotary cam 32 provided with an annular rim 33 projecting from the bell side thereof and having a practical plurality of laterally projecting circumferential peaks. These peaks have a camming edge 34, a summit and a shoulder 35 with which the arm 22 adjacent the head l6 of the striker S is adapted to co-act in a man- 'ner to be later described.

A control member C comprises a disk 36 having a central opening 31 sufficiently large to freely receive the hub 29 between the disk 30 and cam 32 so as to mount the disk 36 for transverse or radial movement relative to the platen shaft l0.

At a location directly below the center of the disk 36 a relatively large wheel, constituting a paper rider or rolling rider 39, is rotatably mounted on the side of the disk confronting the rotary cam 32. A yoke 40 projects from an L- shaped arm 41 secured by a set screw 42 to the usual paper finger carrying shaft 43 which is supported in the bearings ll of the carriage in parallelism with and at the rear of the platen as will be understood by those familiar with the art.

The yoke 40, which is vertically disposed, co-

a guide a sheet around the latter. At the loweracts with two relatively small rollers 44 rotatably mounted on the disk 36 at opposite sides of the axis thereof, so as to confine the disk 36 against rotation and yet permit transverse or radial movement of the disk.

Under the action of gravity, the disk 36 occupies a lowered position shown in Figure 6 wherein the disk is supported clear of the hub 29 by one of the rollers 44 which rests upon a lateral extension or foot 40a on that one of the legs 40b of the yoke 40 towards the front or keyboard side of the typewriter, the other leg 400 having a rectilinear extension 40d co-acting with the respective roller 44 in the lowered position of the disk 36 to aid in its support and to prevent rotation of such disk in either direction, as will be understood from a consideration of Figures 5 most point of the recess 45, the fioor thereof has an opening 45a through which any foreign substance liable to interfere with the full and free downward movement of the wheel 39 will be free to discharge. However, a walled recess is made in the deflector only when a transverse open slot of sufficient length is impractical because of a marginal cut out that a skilled mechanic is unable to shift or shorten.

At diametrically opposed points on the disk 30 are two contact pins 41 which are fixed to the disk and present knife or sharp edges radially inward of the disk. One or the other of the pins 41 is adapted to be engaged by a holding pin 50 projecting from the disk 36 vertically above its center, when the disk occupies its raised position under the action of a sheet of paper extended around the platen, all to the end of providing an operative connection between the disks 30 and 36 to temporarily prevent the disk 30 from rotating. The holding pin 56 presents a knife edge radially outward oi the disk 36 for co-action with the knife edge of either of the contact pins 41 in insuring proper stopping engagement therewith in the operation of the invention, which is as follows:

Under the action of gravity, the control member C occupies its lowered position shown in Figure 6, wherein the rolling rider 39 projects downwardly beyond the periphery of the platen and the holding pin 50 is clear of the path of rotation of the contact pins 41.

Upon inserting a sheet of paper and initiating rotation of the platen in a direction to advance the paper, the wheel will co-act with the paper to raise the control member C and hence raise the holding pin 59 into the path of rotation of the pins 41. It will be understood that the ring 23 is caused to rotate with the platen because of the frictional driving connection between the ring and platen provided by the undulated spring 25. As advancing movement of the platen is continued, the first one of the pins 41 which touches the pin 50 will co-act therewith to initiate winding of the spring 26, as the inner end of this spring is anchored to the locked hub 29 of the disk 36, and the outer end of the spring is fixed to the ring 23.

It will be noted that by the provision of the relatively sharp edges which the pins 41 and 50 present to each other in directions radially of the disk 30, there is no possibility of the pin 50 failing to move into the path of rotation of the pins 41 even though one of the latter should be struck by the pin 50 during its rising movement, as under such condition the pin 50 will be free to slip by the pin 41 into the path of rotation of the latter, so as to insure a dependable operative connection between the disks 30 and 36. This positiveness in action is further insured by the fact that the spring 26 has practically no tension when the sheet of paper is inserted, so that the contact pins 41 are free to adjust themselves to any relation of the holding pin 50, whereby the latter will never engage an edge of the contact pm and be prevented from moving upwardly into the path of rotation of the latter; also by the fact that the contact pins are in rapid motion when the sheet is twirled in; even if the impossible happens the only change from the normal is a slight dipping of the paper under the rolling wheel followed by instant. recovery.

As the cam-32 is being held against rotation,

and the bell B is being rotated by the platen, the arm 22 of the striker S will engage a shoulder 35 of the cam. The striker will be held against rotation by the cam and will permit the bell to freely rotate, as the tendency of the coil is to unwind and release its frictional hold on the hub I9 during advancing movement of the platen.

As the platen continues to advance during the typing operation, the spring 26 is being wound, and when the bottom edge of the paper clears the rolling rider 39, the control member C instantly gravitates to its lowered position shown in Figure 6, thus disengaging the holding pin 50 from that one of the contact pins 41' with which it has been co-acting to arrest rotation of the disk 30.

The spring 26 now instantly rotates the disk 30 and the cam 32 in the direction corresponding to advancing movement of the platen, thus causing the shoulder 35 which has been co-acting with the striker arm 22 to leave the latter, and the plurality of inclined camming edges 34 to successively move the arm 22 against its normal tendency to maintain the head l6 clear of the bell, thus causing the head to positively strike the bell in very rapid succession to produce a clearly distinguishable signal to the operator that the last permissible line is being typed.

By normally spring urging the striker head It away from the bell B, and by positively forcing the striker S into contact with the bell under the action of the cam 32, to sound the signal, there is no possibility of an intrusive sounding of the bell upon retrograde movement of the platen P which is effected to turn back the sheet for corrections. This is due to the fact that during retrograde movement of the platen, the striker arm 22 slowly rides upon the inclined cam surfaces 34 and drops therefrom away from the bell 14.

By increasing the number of contact pins 41 carried by the power disk 30 its possible idle movement with the platen may be reduced and the beginning of the winding of the spring 26 stepped up, resulting in an increased spring tension when the platen is twirled to receive a sheet of paper; similarly, a practical plurality of camming edges 34 amplifies the signal by lessening the idle movement of the rotary cam 32. The work of the holding pin 50 carried by the mother disk 36 of the control member C is to arrest a moving contact pin 41 and hold it with the least possible resistance to insure the action of gravity on the control member C when it is no longer supported by the paper, and as a position above increases its distance from the shaft I and a position below decreases its distance when a paper is inserted the well known law as distance increases, pressure and friction decrease establishes the location of the holding pin 50 above the shaft.

The twin wheels 44 carried by the mother disk 36 are slightly spaced from the legs of the yoke 40; they look each other opposingly against the fixed legs of the yoke when the paper moves in either direction, to prevent rotary displacement of the control member C. When one of the legs with its extension is made rectilinear throughout, the extension is not lost, only its visual differentiation from the leg is lost, and it does not become a non-essential part; owing to the necessary spacing of the twin wheels from the yoke, the rear wheel drops below the leg with the dropping of the control member and is arrested by the vertical extension. The lateral displacement of the control member C is prevented by the legs of the yoke and'the rotary cam 32 on one side and by the power disk 36 and the end of the platen P on the other, the holding pin 60 and contact pins 41 spanning the space between the power disk 30 and the mother disk 36 of the control member. A sister wheel slightly spaced lbetween the legs of the yoke near the top and carried by the control member may or may not be used. Such a wheel is not shown in the drawing. The duties of the legs of the yoke 46 are to guide, resist, arrest, confine andsupport the twins 44; they also stand as sentinels to guard against escape to the left of the imprisoned parts.

Should a sheet exceptionally long fully wind the spring 26, the ring 23 releases its frictional grip and slips within the member I3 to prevent breakage of the spring.

The power disk 30, the rotary cam 32, the connecting portion of the hub 29, the toothed portion of the hub 29, and the control member C may be collectively thought of as a spool encircled by a mother disk 38 spaced from the connecting hub, the spool being closely but freely mounted on the shaft ill and extending from the bottom of the cup l3 to the striker S.

The cup l3 fits tightly into and is a part of the platen P; its bottom has a central hole just large enough to receive the shaft l0 without binding it against longitudinal movement, the cup provides a stable bearing for the loosened end of the platen and an inner chamber for housing the major portion of the working parts. The coil I1 is wound clockwise around the recessed hub of the bell and grips it slightly.

When the paper is absent a turning of the platen P forward or backward effects nothing; however, when a sheet is twirled in, the parts instantly take notice of its presence with a number of changes. The twins 44 spring into position against the legs 40b and 400 of the yoke 46 to resist rotary movement of the mother disk 36; the rolling rider climbs upon the paper, lifting the control member C and bringing the holding pin 50 into its arresting position; a contact pin 41 moves up against the holding pin, locks the toothed hub 29 at the center of the coil and begins its work of winding the spring 26 while the striker S moves up against the shoulder of the rotary cam 32 and finding it locked releases its grip on the smoothed recessed hub I9.

As the work progresses the tension of the spring 26 and the pressure against the holding pin 56 increase while the ability of the undulated spring 25 to maintain its frictional hold on the platen P and on the ring 23 progressively weakens and becomes naught when the spring 26 is fully wound. The friction progressively built up by the increasing pressure against the holding pin 50 never reaches a gravity resistance suflicient within itself to support the entire weight of the control member C, the paper never being wlholly relieved of its burden.

With ordinary sheets of paper the spring 26 is never fully wound, however, sheets of unusual length fully wind it and the undulated spring 25 is called upon to break its frictional hold upon the platen P and becomes stationary with the locket ring 23, or break its frictional hold on the ring and move on with the platen; it obeys the mandate as, it will be remembered, its power to hold against the fully wound spring 26 is reduced to zero.

When the sheet passes from under the rolling rider 39 the control member C drops by the action of gravity, thereby releasing the tensioned spring 26 and permitting its inner end to unwind pulling the toothed hub 29, the power disk -and the rotary cam 32 around with it, the outer end of the spring being frictionally anchored to the platen. This action of the spring, independent of the platen movement, brings a camming edge 34 up against the striker S which, to prevent being pushed around with the rotating cam 32, tightens its grip on the hub 19 and is compelled by the quick passing of the camming edges 34 and summits to strike the bell B, instantly retrieving, however, its normal position away from the bell. It is a caution, not a stop signal, if the typist is within one or two lines of completion. I

Backward turning of the platen to make a correction is permitted at any time, even after the sounding of the signal, the parts co-operating in reverse as well as direct movement.

In retrograde movements of the platen the striker S moves from a shoulder to a camming edge 34, tightens its grip on the (hub l9, climbs the slope, passes over the summit and springs away without striking the bell, the momentum of its head l6 being insufficient to overcome the restraining tension of its arm 22; thanks to the inability of the fingers to duplicate the performance of the faster moving spring.

Unlike the striker, a contact pin 41 does not.

move away from the holding pin 50 but merely lessens its pressure against it progressively until the spring 26 is entirely unwound; then if the sheet is of unusual length it moves away as another contact pin 41 moves up to the holding pin 50 from the other side; now the inner end of the spring 26 leaves its anchorage and moves around over the ratchet teeth 28 of the locked hub 29; also, there is a slight shifting of the twins M. While a direct contact pin 41 and a reverse one are shifting their positions the power disk 30, and with it the toothed hub 29 and rotary cam 32 are given a limited freedom to move with the platen. The spring 26 winds and unwinds from its outer end with the movement of the platen; however, with the dropping of the control member C it unwinds from its inner end. The signal synchronizes with the movement of the line space lever; as the conventional line signal is heard at the end of a line so my sheet signal sounds at the beginning of a line; and as the one safeguards the line, so the other safeguards the sheet.

While the movement of the parts is somewhat difllcult to follow, the device is simple and consists of but few parts.

Should the mechanismbecome damaged and inoperative, all that is necessary is to cut out the disabled device by inserting the sheet of paper a little farther to the right. The machine will then function as an ordinary typewriter without the necessity of having the damaged member repaired. But let it be understood that the signaling device is simple in construction, strongly built and has a lifetime of efiicient service equal to that of the typewriter itself.

The minimum length of signal sounding sheets is around three inches; the maximum length is unlimited.

What is claimed is:

1. In a typewriter, a platen; a signal comprising a bell and a striker for sounding the bell; a rotary actuator having means with which the striker co-acts to sound the bell in response to rotation of the actuator in one direction; a spring operatively connecting the platen and rotary actuator and adapted to be wound when the platen is rotated to advance a sheet of paper and said actuator is held against rotation; a control member; means confining the control member against rotation and mounting the latter for vertical movement transversely of the platen axis to normally gravitate to a lowered position; means on the control member adapted to co-act with a sheet of paper when extended around the platen, in moving thecontrol member to a raised position; said actuator having a plurality of fixed contact pins at circumferentially spaced points, and the control member having a holding pin movable into and out of the path of rotation of the contact pins according as the control member is raised or lowered, to accordingly prevent or permit rotation of the actuator, whereby to wind the spring during the typing operation and to sound the signal when the bottom edge of the sheet clears the paper co-acting means; said pins being shaped to present such small area to each other as to minimize the possibility of the contact pins obstructing movement of the holding pin into the path of rotation of the contact pins should one of the latter be struck by the holding pin during the aforesaid movement thereof.

2. In a typtwriter, a platen; a signal com prising a bell and a striker for sounding the bell; a rotary actuator having means with which the striker co-acts to sound the bell in response to rotation of the actuator in one direction; a spring operatively connecting the platen and rotary actuator and adapted to be wound when the platen is rotated to advance a sheet of paper and said actuator is held against rotation; a control member; means confining the control member against rotation and mounting the latter for vertical movement transversely of the platen axis-to normally gravitate to a lowered position; means on the control member adapted to co-act with a sheet of paper when extended around the platen, in moving the control member to a raised position; said actuator having a plurality of fixed contact pins at circumferentially spaced points, and the control member having a holding pin movable into and out of the path of rotation of the contact pins according as the control member is raised or lowered, to accordingly prevent or permit rotation of the actuator, whereby to wind the spring during the typing operation and to sound the signal when the bottom edge of the sheet clears the paper co-acting means; said pins presenting relatively sharp parallel edges to each other in the direction of movement of the holding pin into the path of rotation of the contact pins so as to prevent the latter pins from obstructing such movement of the holding pin should the latter strike one of the contact pins.

3. In a typewriter, a platen; a signal comprising a bell and a striker for sounding the bell; a rotary actuator having means with which the striker co-acts to sound the bell in response to rotation of the actuator in one direction; a spring operatively connecting the platen and rotary actuator and adapted to be wound when the platen is rotated to advance a sheet of paper and said actuator is held against rotation; a control member; means confining the control member against rotation and mounting the latter for vertical movement transversely of the platen axis to normally gravitate to a lowered position; means on the control member adapted to co-act with a sheet of paper when extended around the platen, in moving the control member to a raised position; the actuator and control member having fixed pins co-actable in the raised and lowered positions, respectively, of the control member, to prevent or permit rotation of the actuator, whereby the spring will be wound during the typing operation and the bell will be sounded when the bottom edge of the sheet clears the paper co-acting means; the pins presenting such relatively small areas to each other in the direction of rising movement of the control member that incomplete rising movement of the latter due to the pins obstructing such movement, will be obviated.

4. In a typewriter, a platen; a signal comprising a bell and a striker for sounding the bell; a rotary actuator having means with which the striker co-acts to sound the bell in response to rotation of the actuator in one direction; a spring operatively connecting the platen and rotary actuator and adapted to be wound when the platen is rotated to advance a sheet of paper and said actuator is held against rotation; a control member; means confining the control member against rotation and mounting the latter for vertical movement transversely of the platen axis to normally gravitate to a lowered position; means on the control member adapted to co-act with a sheet of paper when extended around the platen, in moving the control member to a raised position; the actuator and control member having fixed pins co-actable in the raised and lowered positions, respectively, of the control member, to prevent or permit rotation of the, actuator, whereby the spring will be wound during the typing operation and the bell will be sounded when the bottom edge of the sheet clears the paper co-acting means; the holding pin having a position on the control member above the platen shaft so as to move away from the platen axis during rising movement of the control member so as to lessen the tendency oi the spring to prevent disengagement oi the pins when lowering movement of the control member should take place.

5. In a typewriter, a platen; a signal comprising a bell and a striker for sounding the bell; a rotary actuator having means for energizing and'releasing the striker to sound the bell in response to rotation of the actuator in one direction; a spring operatively connecting the platen and rotary actuator and adapted to be wound when the platen is rotated to advance a sheet of paper and said actuator is held against rotation; means controlled by a sheet of paper to prevent rotation of said actuator or free the latter for rotation by the spring according as th paper is extended around the platen or the lower edge of the sheet reaches a predetermined position, whereby to wind the spring during the typing operation and to sound the signal when the sheet has been advanced to the predetermined position; and means co-acting with the actuator and spring to prevent damage to the spring in response to unwinding movement imparted thereto beyond its fully unwound position.

6. In a typewriter, a platen; a signal comprising a bell and a striker for sounding the bell; a rotary actuator having means for energizing and releasing the striker to sound the bell in response to rotation of the actuator in one direction; a spring operatively connecting the platen and rotary actuator and adapted to be wound when the platen is rotated to advance a sheet of paper and said actuator is held against rotation; means controlled by a sheet of paper to prevent rotation of said actuator or free the latter for rotation by the spring according as the paper is extended around the platen or the lower edge of the sheet reaches a predetermined position, whereby to wind the spring during the typing operation and to sound the signal when the sheet has been advanced to the predetermined position; and a ratchet and pawl connection between the actuator and spring for preventing damage to the latter should unwinding movement be imparted to the spring when fully unwound.

JAMES Y. PAY'ION.

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