Attachment for converting a standard typewriter to a self-correcting typewriter

Claim 2

An attachment device for use with a typewriter of the type that has a keyboard, a backspace means and a ribbon selector, comprising first and second keys including control means for operating said backspace means of the typewriter when either of said first or second keys is depressed, and movable means which when said first key is depressed positions said ribbon selector in a first position and which when said second key is depressed positions said ribbon selector in a second position, and frame means for attaching said device to the typewriter to position the device external to the typewriter in a position such that said control means is in operative relation to said backspace means and said movable means is in operative relation to said ribbon selectoR.

Claim 3

An attachment device as defined in claim 1 for use with a typewriter in which the backspace means comprises a backspace key near one end of the keyboard and the ribbon selector includes an operating control arm near the opposite end of the keyboard, said frame means extending under the typewriter and also extending upward along opposite sides of the typewriter, said control means being adjacent said backspace key and said movable means being adjacent said control means, said movable means and said control means being interconnected under the typewriter and adjacent the said frame means of said device.

Claim 4

An attachment device as defined in claim 1 for use in a typewriter of the type in which the backspace means includes a backspace key and the ribbon selector includes a control element adjacent the backspace key comprising said frame means for the attachment device including means for attaching said frame means to a portion of the typewriter adjacent said backspace key, said frame means comprising an enclosure, said first and second keys extending out of said enclosure, and said movable means including means extending out of said enclosure to engage said control element.

Claim 5

In a typewriter, a frame, typing means including a keyboard carried by said frame, backspace means including an element for operating the backspace means, ribbon selector means including a mechanism for operating the ribbon selector means, a casing carried by said frame and at least partially extending around some of the operating parts of the typewriter, the keyboard, said element and said mechanism extending out of said casing, and a device attached to said typewriter and positioned outside of said casing, said device comprising: a. first and second keys b. means which when either of said keys is depressed operates said element to effect a backspace operation, and c. means which operates said mechanism to insure that the ribbon selector means is in one position after the first key has been depressed and is in another position after the second key has been depressed.

Claim 6

In a typewriter, a frame, typing means including a keyboard carried by said frame, backspace means including an element for operating the backspace means, ribbon selector means including a mechanism for operating the ribbon selector means, a casing carried by said frame and at least partially extending around some of the operating parts of the typewriter, the keyboard, said element and said mechanism extending out of said casing, and a device attached to said typewriter and positioned outside of said casing, said device comprising: a. first and second keys b. means which when either of said keys is depressed operates said element to effect a backspace operation, and c. means which operates said mechanism to insure that the ribbon selector means is in one position after the first key has been depressed and is in another position after the second key has been depressed.

Claim 7

An attachment for an existing typewriter that will give it additional functions, said typewriter having backspace means including a backspace key, a ribbon having a plurality of printing fields and also having ribbon field selecting means including a manually operable device for controlling the ribbon printing field selecting means for selecting one of the printing fields of the ribbon, comprising: mounting means carrying the attachment and adapted to be attached to an existing typewriter, a first key carried by said mounting means, a second key carried by said mounting means, supplementary backspace means operated by the depression of either of said first or second keys for operating the backspace means that is a part of the existing typewriter, all without preventing the typist from operating said backspace means that is a part of said typewriter, and supplementary ribbon field selecting means which operates the ribbon field selecting means that is on the existing typewriter, to insure that said ribbon field selecting means that is on the existing typewriter is in one position after said first key has been depressed and is in another position after said second key has been depressed, without preventing the typist from also manually selecting the printing fields of the ribbon by operating said ribbon printing field selecting means that is on the existing typewriter.

Claim 8

An attachment for an existing typewriter that will give it additional functions, said typewriter having backspace means including a backspace key, a ribbon having a plurality of printing fields and also having ribbon field selecting means including a manually operable device for controlling the ribbon printing field selecting means for selecting one of the printing fields of the ribbon, comprising: mounting means carrying the attachment and adapted to be attached to an existing typewriter, a first key carried by said mounting means, a second key carried by said mounting means, supplementary backspace means operated by the depression of either of said first or second keys for operating the backspace means that is a part of the existing typewriter, all without preventing the typist from operating said backspace means that is a part of said typewriter, and supplementary ribbon field selecting means which operates the ribbon field selecting means that is on the existing typewriter, to insure that said ribbon field selecting means that is on the existing typewriter is in one position after said first key has been depressed and is in another position after said second key has been depressed, without preventing the typist from also manually selecting the printing fields of the ribbon by operating said ribbon printing field selecting means that is on the existing typewriter.

Claim 9

An attachment for an existing typewriter as defined in claim 5 in which both the supplementary backspace means and the supplementary ribbon field selecting means is carried by said mounting means, so that the entire attachment is a single unit.

Claim 10

An attachment as defined in claim 5 in which the supplementary backspace means comprises an arm that overlies the backspace key of the existing typewriter when the attachment is mounted on said typewriter, Said arm being movable downwardly in event the typist presses said arm, thereby permitting the typist to press it in order to operate the backspace key of the existing typewriter.

Claim 11

An attachment for an existing typewriter as defined in claim 6 in which: the supplemental backspace means comprises an arm that overlies the backspace key of the existing typewriter when the attachment is mounted on said typewriter, said arm being movable downwardly in event the typist depresses said arm thereby permitting the typist to depress said arm in order to operate said backspace key, and the supplemental ribbon field selecting means engages the ribbon field selecting means of the existing typewriter to control the ribbon field selection.