US2558280A - Mechanically operated eraser for typewriters and the like - Google Patents

Description

June 26, 1951 w. H. TAYLOR 2,558,280

MECHANICALLY OPERATED ERASER FOR TYPEWRITERS AND THE LIKE 4 Sheets-Sheet 1 Filed Oct. 14, 1948 INVENTOR: Mum/4H. 1 a YL 0R,

1 NEy.

ATTOR June 26, 1951 w. H. TAYLOR 2,558,280 MECHANICALLY OPERATED ERASER FOR TYPEWRITERS AND THE LIKE Filed Oct. 14, 1948 4 Sheets-Sheet 2 INVENTQRJ LEW/AR HT TOENEY.

MLL/RII H.

June 26, 1951 w. H. TAYLOR Y 2,558,230

MECHANICALLY OPERATED EHASER FOR TYPEWRITERS AND THE LIKE Filed Oct. 14, 1948 4 Sheets-Sheet 3 I Izvwsivrom MLL/HM H. THYLOR 80a.

2 2, wa /%z-./ 2.5a. 80a. 28 25 j ATTORNEY- June 26, 1951 w. H. TAYLOR MECHANICAL-LY OPERATED ERASER 1 FOR TYPEWRITERS AND- THE LIKE 4 Sheets-Sheet 4 Filed 001;. 14, 1948 I N vsu "roe.- TA LOR,

A -r roams y.

Patented June 26, 1951 MECHANICALLY OPERATED ERASER FOR TYPEVVRITERS AND THE LIKE William H. Taylor, Big Bear Lake, Calif. Application October 14, 1948, Serial No. 54,392

13 Claims.

notes; in short, corrections involve small erasures since extensive erasing results in untidy appearance so that a page requiring such extensive correction is generally rewritten. It is by no means easy to erase a single typewritten character Withoutmarring adjacent characters even when using the smallest holes in the usual erasing shield, While the pressure exerted against the shield while the typist erases will usually smudge the carbon copies unless precaution is taken to mask them, but typists often neglect to take such precautions because of the extra time and efiort required.

In order to save time and eifort spent in hand erasing of typewritten work various mechanical erasure fittings for typewriters have been previously proposed but to the best of my knowledge have not come into use.

It is the general purpose of my invention to provide a fitting for typewriters which may be readily attached to a typewriter or built intosuch machines and which will perform more satisfactorily than any devices of the kind of which I am aware and which affords results superior to hand erasing.

It is an object of my invention to provide a mechanicaleraser mounted on the typewriter and embodying an erasing element which will accurately erase a single character at each operation, repeated operations of the erasing element not: affecting its accuracy either in positioning of the element or in its operative functioning.

A further object of my invention is to provide ,an automatic erasing device mounted to operate at the point reached by a character after the type key has been released, but which is normally held out of the way of the type bars.

It is another object of my invention to provide .a mechanically operated eraser which when operated by the depression of a lever moves the erasing element with a short stroke swing movement accurately over the position of the character to be erased and in contact with the paper, continued depression of the key running a sufficient length of erasing material the width of the character over the latter to satisfactorily erase it without exerting such pressure on the paper as. to cause smudging of the carbon copies, or cause shifting of the paper on the platen.

A still further object of my invention is to provide an erasing fittingv as set forth in the preceding paragraph which may optionally be provided with mechanism effective on still further depression of the key to return the portion of the paper from which a character has been erased to the type impact point so that another character may be typed thereon, or may not be fitted with such additional mechanism in which case the back space key of the typewriter is utilized to bring back the erased portion of the paper to the typing point.

Another object of my invention is to provide a mechanically operated erasing device provided with means to press the erasing element against the paper on the typewriter platen, said means coming into operation after the erasing element is in operative position but before said element is given its erasing movement.

Yet another object of my invention' is to pro- .vide an erasing device of the kind described in which the erasing element is formed to remove the undesired character with a smoothness at least equal to the best hand erasing in contradistinction to erasing devices which in efiect scratch off the surface of the paper with the erased character and so mar the appearance of the typed sheet.

Another object of my invention is to provide an erasing device of the kind described in which the erasing material is formed as an extended length or endless band guided over the whole extent of the character to be erased from top to bottom and side to side but not marring the appearance of an adjacent character, a suflicient length of the erasing material being passed over the character under pressure adequate to completely erase it in one operation, the continuous feeding of fresh erasing material ensuring uniformity of erasing action throughout the length of the strip or endless band.

Yet another object of my invention is to provide an erasing device as set forth in the preceding paragraph in which the amount of pressure exerted by the erasing element against the paper A further object of my invention is to provide a simple and trouble-free erasing device which may be readily fitted to or incorporated in typewriters of various standard makes.

Still further objects and features of my invention will hereinafter appear from the following description taken in conjunction with the accompanying drawings in which is illustrated an embodiment of the invention at present deemed preferable by me, but it is to be understood that various modifications may be effected by those skilled in the art without departing from the scope of the invention as intended to be defined by the appended claims.

In the drawings:

Fig. 1 is a fragmentary detail view in front elevation and to approximately full size of the eraser head and eraser ribbon feed of my invention, various parts of the associated operating mechanism being omitted for clearness, the eraser head being shown in inoperative position;

' Fig. 2 is an enlarged view of the eraser head alone in operative position;

Fig. 3 is a section on the line 3-3 of Fig. 2;

Fig. 4 is a View in side elevation looking in the direction of the arrows 11-4 in Fig. 2;

Fig. 5 is a fragmentary view in section and drawn to a larger scale showing the pressure plate of Fig. 3 pressed against the paper on the typewriter platen P;

Fig. 6 is a view similar to Fig. 5, but showing the pressure plate relieved of pressure;

Fig. '7 is a fragmentary view in perspective drawn to a large scale of a pressure plate mounted on the face oi the eraser head;

Fig. 8 is a section on the line 8-3 of Fig. l, the mechanism being shown immediately after the swinging arm has been erected and just previous to the application of pressure thereto;

Fig. 9 is a side elevation looking in the direction of the arrows 99 of Fig. 1;

Fig. 10 is a perspective View of a member efiective to apply pressure to the erasing head;

Fig. 11 is a perspective view of a member effective when actuated to move the erasing head from inoperative to operative position and to draw the erasing head to inoperative position when released;

Fig. 12 is a perspective view or" a two-part main eraser operating lever;

Fig. 13 is a cross section on line {3-43 of Fig. 9 with parts omitted for clarity;

Fig. 14 is a rear elevation with parts omitted for clarity;

Fig. 15 is a perspective view showing back spacing mechanism disassembled from the remainder of the eraser mechanism;

Fig. 16 is a plan view of the parts shown in Fig. 15;

Fig. 1'? is a detail view in side elevation of a swinging plate actuated by the operating lever on its return movement to work the back spacing prises a vertical main plate 24 which, in the form shown in the drawings, is secured by threaded machine screws 24a to the side frame 22, most of the mechanism of the device being carried on this plate which is generally of the extent of the 4 side of the mechanism containing portion of the typewriter frame.

A secondary plate 26 is arranged to extend parallel to plate 24 being secured at top and bottom to top and bottom flanges and 25a, respectively, extendin from plate 24 and slopes from the keyboard end of plate 24 upwardly and rearwardly.

The mechanism is operated by a lever 28 which in a single movement operates a plurality of mechanisms effecting the following operations which will be each explained:

Swings the erasing parts from inoperative to operative position.

Presses the erasing element against the paper.

Pulls the erasing element, which is in the form of a ribbon, across the character to be erased and if the back spacing key of the typewriter is not desired to be used for the purpose, back spaces the erased portion of the paper to typing position.

The erasing parts comprise a narrow length of erasing material such as a ribbon about fi" wide having a surface incorporating finely ground abrasive powder. The eraser ribbon may be either an endless band or a length of ribbon wound on a spool.

The ribbon is fed in taut condition by feed rollers to an erasin head carrying applicator means and which is normally positioned out of the path of the type bars but is brought into operation as will be now described.

In the drawings I show an eraser element 30 in the form of an endless band led between a pair of pulleys 32, 33 preferably having peripheries of resilient material. The pulley 32 is mounted on a bushing 32a (Figs. 8 and 9) on which a gear 32b is also mounted and bushing 32a is pinned to a shaft 34 rotatably mounted in bracket 34a projecting from plate 24. At the opposite end of shaft 34 a pulley 36 is mounted to rotate freely between a collar 36a. and a ratchet wheel 38 formed with a collar 38a which is pinned to shaft 3 5. A pawl 48 is pivoted on the side of pulley 36 and is resiliently held in engagement with the ratchet wheel by a spring 40a.

A cord 42 is secured at one end to a clamp 42a on a flange of the pulley and Wound around the pulley, the free end of the cord being secured to a lever 44 hinged at one end to the bottom flange of plate 24. The pulley 36 is resiliently urged to rotate in a direction to keep the cord 42 wound on the pulley 36 by a helical torison spring 46 surrounding shait 34 and having one end secured to a flange of pulley 36 by pin 66a and having its opposite end secured to the plate 24. Lever 44 is depressed by operating lever 28 during the latter part of its movement as will be described hereinafter.

An abutment 48 mounted on plate 24 serves to limit the upward movement of lever 44 under the pull of cord 42 and the action of spring 46. The upper eraser band feeder ulley 33 is mounted on a sleeve 33a together with a gear wheel 33b identical with gear 32b, the sleeve 33a rotating freely on a cranked end 50a of a short shaft 50 mounted in brackets 52?) projecting from plate 24. A tension spring 500 hooked at one end to cranked end 50a of shaft 58 and at the other end to a bracket 50d serves to keep the gears 32!) and 33b in mesh and the resilient peripheries of pulleys 32 and 33 pressed together gripping the eraser ribbon between them.

Below pulley 32 a take-up pulley 52 is mounted on the cranked end 5401, of a short shaft 54 mounted in bearing brackets 54b projecting from plate 24. A tension spring 540 is hooked at one end over crank 54a, and at the other end is secured to the bottom flange of the housing.

The top and bottom runs of the eraser band are guided horizontally by a guide pulley 56 carried on a bracket 56a secured to plate 24, and a pulley 51 serves to guide a vertical run of the eraser ribbon between the take up pulley 56 and the upper horizontal run of the eraser.

The eraser head is shown in detail in Figs. 2 through 7 and comprises a swinging arm 58 pivoted on a pin 66 projecting from a bracket 62 eX- tending across and secured as by screws 62a to vertical posts located at each side of the type bar printing position in the type of machine to which the invention is shown applied. The posts are carried on a member of the typewriter that rises vertically with the platen P when the shift keyis used to bring the platen in position to receive upper case or capital letters, and the eraser head operation is therefore unafiected when the typewriter is so operated.

One of the holes in bracket 62 for screws 62a is preferably vertically elongated to enable a slight adjustment of the upper end of the eraser head to be made for a reason later explained.

Arm 58 is provided with a laterally projecting lug 53a adapted to contact an adjustable stop provided by a threaded stud 62b screwed into a threaded hole in a lug 62c struck out of bracket 62.

The upper end of arm 58 i provided with a pressure plate 581) of a size and curvature to cause the eraser ribbon to cover and bear against a single typed character on the paper mounted on the platen and over this pressure plate a length of the eraser ribbon is fed at each operation of the lever 28. Means for applying a desired pressure of plate 5% against the eraser ribbon and paper on the platen will be described later.

The eraser ribbon is fed over a system of guide pulleys mounted on the swinging arm 58 and comprising a pulley 64 preferably mounted on pivot 60, a pulley 66 mounted to project beyond the free end of the swinging arm and mounted on a pin supported in cars 58c bent up from arm 58, a pulley 68 mounted below pulley 66 and a pulley H3 mounted adjacent the pulley 64, all of the pulleys being mounted on the longitudinal axis of the swinging arm 58. Pulley 68 is preferably mounted at one side only to facilitate insertion of the eraser ribbon from the open side. This is provided for as shown in Figs. 2 and 4 by mounting pulley 68 on one end of a small arm 68a pivoted on a threaded and headed pivot pin 68b passed through a slot 680 in arm 68a and screwed into one of the cars 5580 supporting pulley 66. The arm 68a is apertured at its other end to be engaged by the pin supporting pulley 66. By the described arrangement by slacking back pivot 68b pulley 68 may be moved away from the surface of arm 58 to facilitate slipping ofthe eraser ribbon below it. The travel of the eraser ribbon is under pulley 64, through a cut out 580 in arm 58, between the face of pressure plate 58b and the paper sheet on the platen, over pulley 66, under pulley 68 and under pulley III, the direction of movement of the eraser ribbon when operated being indicated by the arrows in Fig. l.

The means for swinging the erasing head into operative position and applying pressure to it will now be described.

An operating rod 12 is pivoted to a projecting ear 12a of swinging arm 58 by pin no, the end of the rod being bent upon itself and machined to lie against the back and front of ear 12a. Means are provided to impart a torque to rod 12 and thereby press the pressure plate 58b toward the platen, and also swing the eraser head swinging arm into vertical position, both operations being effected before running the eraser ribbon across the typed character to be removed, by a single depression of the lever 28, by the mechanism now to be described.

Rod 12 is pushed toward the left as seen in Fig. 1 to bring the eraser head to erect position as shown in Fig. 2 as lever 28 begins a djow'iiward movement by the movement of a U-shaped lever 14 shown in detail in Fig. 11, and in different positions in Figs. 13 and 14. The lever 14 is pivoted by its bottom side Ma in spaced bearings Mb supported on plate 26 and a laterally projecting arm Me is welded to lever 14 between the bearings 74b.

One le of the U-lever is extended upwardly and formed into a loop 14d surrounding operating rod 12 and working between abutment Me and '34.). The shorter leg of the U-lever is in.- wardly bent at Mg and a helical spring Mn is tensioned between the bent arm 14g and a bracket My" projecting laterally from lever 28, and having upwardly turned end 14k positioned to engage with the underside of arm 14c toward its outer end. Since the U-shaped lever has only a slight movement from the vertical the inturned end My serves as an abutment for the spring 74h so that the lever "I4 is normally held in vertical position by the spring pulling bracket end Mic against arm M0 in which position operating rod 12' pulls the erasing head swinging arm into the inoperative position clear of the type bar striking point on the paper. The commencement of a downward movement of lever 28 against the resistance of spring 'F 'lh removes the effort of the end of bracket Mk from arm 14c and the spring 14h then pulls lever 14 outwardly from plate 26 and by engagement of lever arm 14d with abutment Ede moves rod 72 axially winging the eraser head swinging arm 58 into operative position with lug 58a engaged against stop 6%. Although further movement of the eraser head erecting mechanism is arrested at the point described, the lever 28 is enabled to continue its downward movement under the pressure of the operators finger by extension of spring 14h.

The pressure plate 58b on the era-sing head is then moved toward the platen to cause the pressure plate to press the eraser ribbon against the paper on the character to be erased by engagement of a roller 16, projecting laterally from lever 28 and mounted on a bracket 78 secured to the lever, with a tensioning or torque app1y ing arm 80 (Figs. 8, 9, and 10).

Tensioning arm 86 is pivoted at its lower end on a pivot pin 86a mounted in lugs upstanding from the bottom flange 25a of plate 24. At its upper end arm 86 is connected to one end of a helical spring 82, the other end of the spring being connected to an attachment member formed as a small plate 84 having a threaded hole therein. The plate is mounted on a threaded stem 86 carried rotatably in spaced bearing lugs projecting from the longer arm of an L-shaped lever 81, the plate 84 being cut out to embrace said longer arm. The shorter arm of lever 8? is brazed or otherwise secured to rod 12.

The upper end of threaded stem 86 is fitted with a thumb wheel 86a by which the stem may be rotated, thus moving the point of attachmerit of spring 82 downwardly or upwardly so as to give greater or lesser leverage when the upper end of tensioning arm 89 is moved toward the front of the typewriter, acting to twist rod 12 in clockwise direction and thus move the upper end of arm 58 carrying pressure plate 582) toward the platen, there being suilicient play in the mounting of arm 58 for this purpose. Arm 8!! is shown in the drawings as arranged, when the operating lever 28 is also used to back space the platen, to bring the point on the paper from which a character has been erased to the typing point in which case the pressure of the eraser head against the paper must be relieved automatically before the return mechanism is operated although the downward movement of the operating lever is continued. For this reason the roller 15 engages the operating lever through a pivoted member 88 formed as a cam track which automatically moves out of the way of the return of roller 76 when the roller has moved past the end of pivoted member 88, thereby releasing the pressure applying means described before operating the carriage return means.

If it is preferred to use the standard back space key to return the typewriter carriage the member 88 could take the form of a fixed flange on arm 80, the pressure applying means being released on releasing lever 28 before striking the back space key.

The member 88 as shown in detail in Fig. 10 is pivoted at 88a to member 88 and comprises a curved cam portion 88b with an inclined entry portion 880. A compression spring 89 normally holds the upper end of member 88 against an upper stop 88d mounted on arm 80. A lower stop 88a is also preferably provided. The curvature of member 88 is so designed that as roller '15 is moved downwardly it rapidly forces the upper end of member 88 forward while passing down the inclined portion 880, the initial amount of movement taking up the slack in the connection 82 as shown in the dotted line position of arm 8% in Fig. 8, then moves the upper end of the arm still further to the left to the position shown in Fig. 9, by riding down the inwardly and downwardly curved face of member 88, and then holds the arm in operative position while traversing the lower curved portion of member 88 until roller 16 passes beyond the lower end of the member, which lower end is then snapped inwardly by spring 39. When lever 28 is released roller passes over the opposite face of member 88, pushing the upper end of member 88 inwardly momentarily, when lever 23 reaches its upper position, to repeat the described cycle. An abutment 99 on plate 2:. arrests inward or rearward movement of the upper end of arm 80.

A second roller 92 spaced from roller 16 is mounted to project laterally from lever 28 (Fig. 12) and is carried on a stem mounted in a bracket 92a secured to lever 28 this bracket also extending laterally and engaging lever 44 during the downward movement of the lever 28 and causing lever 44 to operate the eraser ribbon feeding mechanism as previously described.

The automatic bacl: spacing mechanism is shown in detail in Fig. 17 and comprises a pair of spaced swinging arms 94 pivoted at their upper ends on studs 94c projecting from plate 24 and at their lower ends pivoted by studs 94?) to a plate 96 which is thus mounted for swinging movement. A pivoted cam strip 98 is mounted at one end by pin 98a on plate 96 to extend perand is again in position pendicularly from the surface of plate 96 and swing over the surface thereof. A spring I00 acts to urge cam arm 98 toward the forward edge of the plate and against a stop War As roller 92 is moved downwardly it presses the lower end of the cam strip away from stop 00a and substantially at the time that roller I6 passes beyond the lower end of member 88 roller 92 passes off the end of cam strip 9.8 which then snaps forward at its lower end and when lever 28 is released roller 92 moves upward, since spring 14h is stressed by the downward movement of lever 28 along the rearward face of the cam strip, and thereby swings plate 96 forwardly.

Plate 96 is connected through rods I02 and [92a and bellcrank [94 mounted on the bottom flange of the fitting to a bent over plate I96 which is drilled to ride on, but engages with the hooked end of, back space rod I98 operated by the back space key Hit and connected linkage of the typewriter. The return spring of the back space mechanism of the typewriter is relied on to return plate 96 to initial position after operation, although obviously a separate spring might be supplied for this purpose if needed.

I prefer to provide a yielding or shock absorbing connection between the plate 96 and rod 802 as shown in Fig. 16, a compression spring H2 being positioned between a head I021) on the end of rod I92 and an car 9611. projecting from plate 96.

While I have described a preferred embodiment of my invention it will be evident that various changes may be made in the construction described; for example the erasing ribbon may be in the form of a length wound on a spool H4 (Fig. 18) which is shown mounted on plate 26 by means of a threaded stud and thumb nut H6 by which sufficient drag may be placed on the eraser ribbon which is then run over suitably arranged guide pulleys H8 and through and over the pulleys previously described. In order to dispose of the used portion of the eraser ribbon outside of the eraser mechanism an additional resilient surfaced pulley I20 and associated gear is provided in place of the take up roller 52. The additional pulley I20 may be mounted in any suitable manner to keep the gear associated therewith in engagement with the gear mounted on the abutting pulley.

I claim:

1. A mechanically operated erasing device for typewriters and the like including: an eraser carrying movable member mounted on a frame member or" the typewriter displaced to type upper and lower case characters and so as to be operative at all times and normally held out of the way of the type bars; an operating member effective to bring the eraser carrying member into operative position relative to the character to be erased; an erasing strip of a width to erase a single character mounted for movement over said eraser carrying member, and means actuated by said operating member effective to move the erasing strip, subsequent to the positioning of the eraser carrying member by the operating member, between the operative end of the eraser carrying member and the paper to erase a single character therefrom.

2. A mechanically operated erasing device for typewriters and the like, including: a pivoted eraser carrying member mounted on a frame member of the typewriter displaced to type upper and lower case characters and so as to be operative at all times but normally held out of the way of the type bars; an operating member; a member operatively connected to the eraser carrying member and to the-operating member and actuated thereby effective to swing the pivoted eraser carrying member into operative position relative to a typed character to be erased, and to press an operative end of said erase carrying member toward the platen of the typewriter; an erasing strip of a width to erase a single character mounted for movement over said eraser carrying member, and means actuated by said operating member effective to move the erasing strip, subsequent to the positioning of the eraser carrying member.

3. A mechanically operated erasing device for typewriters and the like as set forth in claim 2 and in addition comprising parts actuated by the operating member effective to first axially move said member connected to the eraser carrying member to swing the eraser carrying member into operative position and then to apply a torque to said member connected to the eraser carrying member to press the eraser carrying member toward the platen of the typewriter.

4. A mechanically operated erasing device for -typewriters and the like as set forth in claim 2 and in which said operating member is formed as an operating lever pivoted at one end to a frame member; a second lever connected to the eraser carrying member; resilient means :connected to the operating lever and the second lever, downward movement of the operating lever against the resistance of said resilient means first effecting movement of the second lever to swing the eraser carrying member to operative position; a member engaged by further downward movement of the operating lever to press said eraser carrying member toward the typewriter platen; roller means effective to draw a length of eraser ribbon over the eraser carrying member and between it and the paper on the typewriter platen; and a member engaged by the operating lever by still further downward movement thereof effective to rotate said roller means.

5. A mechanically operated erasing device for typewriters and the like as set forth in claim 2 and in which said operating member is formed as a lever pivoted at one end and operated by the application of a downward pressure to the freeend of the lever to swing in a vertical plane; a lever mounted to swing in a plane perpendicular to the plane of movement of the operating lever; a helical spring connected between said operating lever and the second mentioned lever: an arm projecting from said latter lever and a bracket on the operating lever positioned to engage said arm on upward movement of the operating lever to return the second mentioned lever to inoperative position; a rod extending between said second mentioned lever and the pivoted eraser carrying member and effective to swing the said member to and from operative position; a torque transmitting lever fixed to said rod; a torque applying arm positioned to be engaged by said operating lever in its downward movement, said arm being formed so that it is held in the position to which it is moved by the initial downward movement of the operating lever, during the remainder of the downward movement of the operating lever; a connecting member between said torque transmitting lever and said torque applying arm; and means actuated by said operating lever effective to traverse the erasing band, subsequent to the positioning of the eraser carrying member by the operating member, between the operative end of the eraser 10 carrying member and the paper to erase a single character therefrom.

6. .A mechanically operated erasing device as set forth in claim 5, and in which the torque transmitting lever comprises a depending portion, spaced bearings positioned on said depending portion, a threaded stem mounted in said bearings for rotation but held against axialmovement therein, a threaded attachment member displaced upwardly and downwardly on said threadedstem by the rotation thereof by the typist or other user, and a helical tension spring connected at one end to the threaded attachment member and at the other end to said torque applying arm whereby the amount of torque resiliently imparted to said rod may be adjusted by varying the position of said threaded attachment-member.

7. A mechanically operated erasing device for typewriters and the like as set forth in claim 2 and in which the erasing strip is formed as an endless band of abrasive surfaced material; a part, engaged by the operating member .after said operating member has actuated the pivoted-eraser carrying member, effective to pull a predetermined length of the eraser stripat each operation over the operative face of the eraser carrying member, and resilient means stressed by the movement of said operatingmember and effective to return said operating member to initial position.

8. A mechanically operated erasing device for typewriters and the like, including: an arm mounted on the typewriter mechanism adjacent the point of impact of the type bars with the paper on the typewriter platen and so as to be unaffected by manipulation of the typewriter for typing upper and lower case characters, a length of flexible erasing ribbon, means for guiding the flexible length of erasing ribbon movably over said arm and between an operative face thereof adapted to be engaged against the paper on said platen and the paper; eraser feeding rollers mounted to grip the eraser ribbon between their peripheries; guide pulleys for directing said length of eraser ribbon to said arm over and under said arm and back to said rollers; key operated means effecting rotation of said rollers; a member effective to move the arm into operative position and actuated by said key operated means before initiating movement of the eraser feeding rollers; and means actuated by said key operated means eifective to press said arm against said platen after the arm has been moved into operative position and during the movement of the flexible length of erasing ribbon.

9. A mechanically operated erasing device as set forth in claim '8 and in addition comprising backspace means operated by the key operated means and effective to return the platen to bring the point from which the character was erased to the typing point after completion of the erasing operation to receive another character.

10. A mechanically operated erasing device for typewriters and the like as set forth in claim 8 and in addition comprising a movable member mounted for to and fro movement and moved in one direction by the key operated means efiecting rotation of the rollers during the return movement of said key operated means, and linkage connecting said movable member and the backspacing mechansim of the typewriter whereby the latter mechanism is automatically effective to return the portion of the paper from which a character has been erased to the typing position.

11. A mechanically operated erasing device as set forth in claim in which said member mounted for to and fro movement includes a pair of arms each pivoted at one end to a frame member of the device, a vertically arranged plate pivoted to the free ends of said arms for swinging movement, an arcuate cam, strip pivoted at its upper end to said plate and a stop projecting from said plate positioned to prevent movement of the free end of the cam strip in one direction, resilient means holding said cam strip against the stop, and a roller projecting laterally from the key operated means positioned to engage said cam strip and move it away from said stop during movement in one direction, the roller thus passing over the cam strip without moving the plate during said movement but on its return movement engaging the opposite side of the cam strip and swinging the plate to operate the backspacing mechanism.

12. A mechanically operated erasing device for typewriters and the like, including: an arm mounted on the typewriter mechanism adjacent the point of impact of the type bars with the paper on the typewriter platen and so as to be unaffected by manipulation of the typewriter for typing upper and lower case characters; a length of flexible erasing ribbon; means for guiding said flexible length of erasing ribbon movably over said arm and between an operative face thereof adapted to be engaged against the paper on said platen and the paper; eraser feeding rollers mounted to grip the erasing ribbon, a shaft mounted in bearings for rotary movement and connected to one of said rollers, a drum mounted on said shaft, a flexible length of material wrapped around said drum in the inoperative position of said shaft, one end of said length of material being connected to the drum, key operated means effecting rotation of said rollers, a member displaced by the key operated means and to which the other end of said length of material is connected, a spring effective to normally turn said drum in a direction to wind the flexible length of material thereon, and a one-way drive connection between said drum and said shaft operative to rotate said shaft when the drum is rotated by the unwinding of the flexible length of material due to the pull of said member thereon when displaced by the key operated means.

13. A mechanically operated erasing device as set forth in claim 12 and in which meshing gears of identical size are fixed to said erasing ribbon feeding rollers to ensure positive drive of said rollers; and means for urging said rollers into gripping engagement with the erasing ribbon.

WILLIAM H. TAYLOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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