Printing mechanism having a single printing element

Claim 2

A printing mechanism, having a single printing element, for typewriters, teleprinters, accounting and similar printing machines, wherein said printing element is of spheroidal form and has an axis of symmetry which is substantially horizontal, said element being rotatable selectively thereon, said mechanism comprising in combination a cylindrical platen, a forked support carrying said printing element and rotatable selectively about a substantially vertical orientation axis, a base member mounting said support and swingable on corresponding supporting means about a horizontal axis parallel to said platen to cause said printing element to strike said platen, an indexing shaft rotatable on said supporting means and parallel to said platen, a first shaft rotatable in said base member and parallel to said platen, a first train of mutually meshing toothed wheels to connect said indexIng shaft to said first shaft, said wheels being in mesh during the swinging of said base member, an articulated joint connecting said first shaft to a second shaft rotatable in said forked support, said second shaft being parallel to the axis of the printing element, said articulated joint comprising an intermediate element and guiding means included on said first and second shafts for pivotally connecting said first and second shafts to said intermediate element, and a second train of meshing toothed wheels connecting said second shaft to said printing element.

Claim 3

A printing mechanism for typewriters, teleprinters, accounting and similar machines, comprising in combination a supporting paper platen, a barrel-shaped type head rotatable about an axis of said barrel, said type head having circumferential lines of types forming rows in axial planes, a type carrier supporting said type head rotatably about said barrel axis, so that during rotation of said type head said rows are successively positioned in a printing position, a base member supporting said carrier for an angular movement about an orientation axis laying in a plane of symmetry of said type head which is perpendicular to said barrel axis, driving means for selectively rotating said type head on said carrier for placing one of said rows in front of said platen, supporting means pivotally mounting said base member about a swinging axis to cause said type head to strike said platen, a slider selectively movable on said supporting means with respect to said orientation axis along a direction parallel to the swinging axis, a pin fixed to said carrier and having an axis parallel to said orientation axis, and a slot provided on said slider, said slot being perpendicular to said swinging axis and slidingly engaging said pin so that a predetermined shifting of said slider on said supporting means corresponds to a rotation of said carrier for selecting the line of type to be printed, said pin engaging said slot also during the swinging movement of the base member.

Claim 4

A printing mechanism for typewriters, teleprinters, accounting and similar machines, comprising in combination a supporting paper platen, a barrel-shaped type head rotatable about an axis of said barrel, said type head having circumferential lines of types forming rows in axial planes, a type carrier supporting said type head rotatably about said barrel axis, so that during rotation of said type head said rows are successively positioned in a printing position, a base member supporting said carrier for an angular movement about an orientation axis laying in a plane of symmetry of said type head which is perpendicular to said barrel axis, driving means for selectively rotating said type head on said carrier for placing one of said rows in front of said platen, supporting means pivotally mounting said base member about a swinging axis to cause said type head to strike said platen, a slider selectively movable on said supporting means with respect to said orientation axis along a direction parallel to the swinging axis, a pin fixed to said carrier and having an axis parallel to said orientation axis, and a slot provided on said slider, said slot being perpendicular to said swinging axis and slidingly engaging said pin so that a predetermined shifting of said slider on said supporting means corresponds to a rotation of said carrier for selecting the line of type to be printed, said pin engaging said slot also during the swinging movement of the base member.

Claim 5

A printing mechanism according to claim 2, wherein said barrel axis is substantially horizontal, and wherein said orientation axis is substantially vertical and is located in a striking plane which is perpendicular to said platen, said swinging axis being horizontal and parallel to said platen.

Claim 6

A printing mechanism according to claim 3, wherein said type head is selectively rotated by said driving means which comprises a first shaft rotatable in said base member and parallel to said swinging axis, a second shaft rotatable in said carrier and parallel to said barrel axis, an articulated joint connecting said first shaft to said second shaft, and gears connecting said type head and said first shaft.

Claim 7

A printing mechanism according to claim 4 wherein said first shaft is fixed to a first toothed wheel engaging a second toothed wheel rotatable on said base member supporting means coaxially with a substantially horizontal striking axis, said base member swinging about said striking axis to cause said printing element to strike said platen, whereby a constant engagement relation between said first and said second toothed wheels is maintained during said swinging movement of said base member, said gears comprising a third toothed wheel fixed to said second shaft, and a fourth toothed wheel fixed coaxially to said printing element and engaging said third toothed wheel for a unitary transmission ratio between said second toothed wheel and said printing element.

Claim 8

A printing mechanism according to claim 1, wherein said intermediate element comprises an oblong element connected at its two ends by means of two articulations to hollow ends of the first and second shafts respectively, the two articulations comprising two pins parallel to one another.

Claim 9

A printing mechanism for typewriters, teleprinters, accounting and similar printing machines, comprising in combination: a platen, a barrel-shaped printing element rotatable about the aXis of said barrel, said printing element having circumferential lines of characters forming rows in axial planes, said barrel axis being substantially horizontal; a forked support supporting said printing element rotatably about said barrel axis, so that during rotation of said printing element said rows are successively positioned in a printing position, a base member mounting said forked support rotatably about an orientation axis, so that during rotation of said forked support said lines of characters are successively positioned in said printing position, said orientation axis being substantially vertical, striking means supporting said base member for a swinging movement about a striking axis to cause said printing element to strike against said platen, said striking axis being substantially horizontal, said orientation axis being moved on a striking plane perpendicular to said striking axis, first selecting means for rotating said printing element to select a row of said rows of characters to be printed, and second selecting means for rotating said forked support to select a line of said lines of characters to be printed, said first selecting means comprising: a first toothed wheel rotatable on said base member supporting means coaxially with said striking axis, a second toothed wheel rotatable on said base member parallel to said striking axis and engaging said first toothed wheel, whereby a constant engagement relation between said first and said second toothed wheels is maintained during said swinging movement of said base member, a third toothed wheel rotatable on said forked support parallel to said barrel axis of said printing element, an articulated joint connecting said second toothed wheel with said third toothed wheel to prevent said second selecting means from affecting the rotation of said printing element about said barrel axis, and a fourth toothed wheel fixed coaxially to said printing element and engaging said third toothed wheel, whereby a rotation of said first toothed wheel corresponds to a rotation of said printing element about said orientation axis for selecting the row of the character to be printed.

Claim 10

A printing mechanism for typewriters, teleprinters, accounting and similar printing machines, comprising in combination: a platen, a barrel-shaped printing element rotatable about the aXis of said barrel, said printing element having circumferential lines of characters forming rows in axial planes, said barrel axis being substantially horizontal; a forked support supporting said printing element rotatably about said barrel axis, so that during rotation of said printing element said rows are successively positioned in a printing position, a base member mounting said forked support rotatably about an orientation axis, so that during rotation of said forked support said lines of characters are successively positioned in said printing position, said orientation axis being substantially vertical, striking means supporting said base member for a swinging movement about a striking axis to cause said printing element to strike against said platen, said striking axis being substantially horizontal, said orientation axis being moved on a striking plane perpendicular to said striking axis, first selecting means for rotating said printing element to select a row of said rows of characters to be printed, and second selecting means for rotating said forked support to select a line of said lines of characters to be printed, said first selecting means comprising: a first toothed wheel rotatable on said base member supporting means coaxially with said striking axis, a second toothed wheel rotatable on said base member parallel to said striking axis and engaging said first toothed wheel, whereby a constant engagement relation between said first and said second toothed wheels is maintained during said swinging movement of said base member, a third toothed wheel rotatable on said forked support parallel to said barrel axis of said printing element, an articulated joint connecting said second toothed wheel with said third toothed wheel to prevent said second selecting means from affecting the rotation of said printing element about said barrel axis, and a fourth toothed wheel fixed coaxially to said printing element and engaging said third toothed wheel, whereby a rotation of said first toothed wheel corresponds to a rotation of said printing element about said orientation axis for selecting the row of the character to be printed.

Claim 11

A printing mechanism according to claim 7, wherein said second selecting means comprises: a pin fixed to said forked support and having an axis parallel to said orientation axis, a slider slidably mounted on said supporting means along a direction parallel to said striking axis, and a slot provided on said slider, said slot being parallel to said striking plane and slidingly engaging said pin so that a predetermined shifting of said slider on said supporting means corresponds to a rotation of said forked support about said orientation axis for selecting the line of the character to be printed, said pin engaging said slot also during the swinging movement of said base member.

Claim 12

A printing mechanism according to claim 8, comprising: a machine frame, a second slot provided on said slider parallel to said first slot, guiding means on said frame for guiding said base member supporting means for a transverse movement with respect to said platen, said first selecting means comprising a first prismatic shaft parallel to said platen and selectively rotating on said frame, a first hub rotatably mounted on said supporting means and defining a first axial hole having a section corresponding to the section of said first prismatic shaft, said first shaft being slidable axially into said hole and bodily rotatable with said hub, said first hub being fixed to said first toothed wheel, whereby a predetermined rotation of said first prismatic shaft corresponds to a selection of said rows on said printing element, said second selecting means comprising a second prismatic shaft parallel to said platen and selectively rotating on said frame, a second hub rotatably mounted on said supporting means and defining a second axial hole having a section corresponding to the section oF said second prismatic shaft, said second prismatic shaft being slidable axially into said second hole and bodily rotatable with said second hub, a first bevel gear bodily rotatable with said second hub, and a second bevel gear engaging said first bevel gear, said second bevel gear being provided with a pin parallel to said striking plane and cooperating with said second slot, whereby a rotation of said second prismatic shaft corresponds to a selection of said lines on said printing element.

Claim 13

A printing mechanism according to claim 8, wherein each character in the same row of characters is flanked by a pair of wedge-like notches interposed between said characters, and also comprising: a locating member disposed between said printing element and said platen, pivoting means for pivoting said locating member about an axis parallel to said striking axis, spring means for urging said locating member towards said printing element, retaining means for retaining said locating member against the urging of said spring means, said locating member being provided with a forked end located in a first position intermediate between said platen and said printing element on the striking path of said selected character for engagement by the pair of notches flanking the character to be printed for adjusting the position of said printing element, said locating member being dragged by said printing element, whereby said spring means keeps said forked end in engagement with said pair of notches until the striking of said character to be printed on said platen.

Claim 14

A printing mechanism according to claim 10, including a printing cam rotating on said base member supporting means, said retaining means comprising a locating cam angularly fixed to said printing cam, and said locating member including a cam follower contacting at rest a dwell portion of said locating cam under the action of said spring means so as to keep said forked end in said intermediate position, said cam follower leaving said dwell portion during the dragging movement of said locating member, said locating cam having a higher dwell portion to contact said cam follower according to a second position of said forked end closer to said platen than said first position, whereby said forked end disengages said notches adjacent said character immediately after the striking action.

Claim 15

A printing mechanism according to claim 9 comprising a third prismatic shaft rotatable cyclically on said frame of the machine, a third hub rotatably mounted on said supporting means, said third hub being axially slidable on, and rotatable bodily with said third prismatic shaft, said striking means comprising a printing cam fixed on said third hub, and a cam follower of said base member cooperating with said printing cam to cause said base member to swing about said striking axis.

Claim 16

A printing mechanism according to claim 12, wherein said third hub drives cam means for controlling a pair of locating elements after the selective rotation of the first and second prismatic shafts in such manner that one of said pair of locating elements engages said first toothed wheel fixed on said first hub, while the other of said pair of locating elements engages toothing fixed to the slider.

Claim 17

A printing mechanism for typewriters, teleprinters, accounting and similar printing machines, comprising in combination a supporting paper platen, a single type carrier located in front of said platen and carrying a plurality of characters, indexing means for selecting one of said characters, a base member mounting said type carrier, means supporting said base member for allowing said type carrier to strike said platen, a spring having an end fixed to said base member to pull said type carrier towards said platen, a cam follower rigidly connected to said base member, a first printing cam normally contacted by said cam follower under the action of said spring, said first printing cam having a low portion for rapidly releasIng said cam follower at a predetermined angular position of said cam to cause said spring to strike the selected character of said type carrier against said platen, wherein the improvement comprises: a second printing cam synchronously driven with said first printing cam, a spring tensioning member fixing the other end of said spring, said tensioning member including a second cam follower normally contacting said second printing cam under the action of said spring, a supporting member for guiding said tensioning member along a predetermined path, said second cam having a lower profile to cause said tensioning member to be shifted along said path with respect to said base member for modifying the tension of said spring, and arresting means for said tensioning member, said arresting means comprising a number of steps each one associated with a group of said characters having substantially similar printing area, said steps being selectable by said indexing means simultaneously with the selection of any character of said associated group of characters so as to be disposed on said path at different distances from said tensioning member to arrest said tensioning member after different strokes for adjusting the action of said spring on said type carrier according to the printing area of said selected character.

Claim 18

A printing mechanism for typewriters, teleprinters, accounting and similar printing machines, comprising in combination a supporting paper platen, a single type carrier located in front of said platen and carrying a plurality of characters, indexing means for selecting one of said characters, a base member mounting said type carrier, means supporting said base member for allowing said type carrier to strike said platen, a spring having an end fixed to said base member to pull said type carrier towards said platen, a cam follower rigidly connected to said base member, a first printing cam normally contacted by said cam follower under the action of said spring, said first printing cam having a low portion for rapidly releasIng said cam follower at a predetermined angular position of said cam to cause said spring to strike the selected character of said type carrier against said platen, wherein the improvement comprises: a second printing cam synchronously driven with said first printing cam, a spring tensioning member fixing the other end of said spring, said tensioning member including a second cam follower normally contacting said second printing cam under the action of said spring, a supporting member for guiding said tensioning member along a predetermined path, said second cam having a lower profile to cause said tensioning member to be shifted along said path with respect to said base member for modifying the tension of said spring, and arresting means for said tensioning member, said arresting means comprising a number of steps each one associated with a group of said characters having substantially similar printing area, said steps being selectable by said indexing means simultaneously with the selection of any character of said associated group of characters so as to be disposed on said path at different distances from said tensioning member to arrest said tensioning member after different strokes for adjusting the action of said spring on said type carrier according to the printing area of said selected character.

Claim 19

A printing mechanism according to claim 14, wherein said arrest means includes a set of stepped discs of different dimensions, each disc being associated with a corresponding intensity of the striking of said type carrier, said discs being axially slidable on and angularly fixed to a common shaft for being selectively rotated by said indexing means, and comprising a manually operated member for shifting said stepped discs along said common shaft for bringing the stepped disc corresponding to the desired intensity of striking into the path of said tensioning member.

Claim 20

A printing mechanism according to claim 14, wherein said supporting means of said base member comprise a pivot member about which said base member and said second cam follower are individually rotatable, said first cam follower and said second cam follower including corresponding parts adapted to be mutually arrested in order to cause said first cam follower to drag said spring tensioning member after a predetermined stroke in correspondence with said striking action, so that a first part of the striking stroke of said type carrier is effected by the tension of said spring at accelerated speed in dependance on said selected character, and the remaining part of the striking stroke is effected through inertia at substantially constant speed.

Claim 21

A printing mechanism according to claim 16, wherein said type carrier is rotatably mounted on a forked support means for rotating about a substantially horizontal axis, said forked support being rotatable on said base member, said supporting means causing said base member to swing about a horizontal axis, and wherein said indexing means include a first shaft rotatable in said base member and parallel to said platen, an articulated joint connecting said first shaft to a second shaft rotatable in the forked support, said second shaft being parallel to said substantially horizontal axis, and gears connecting said second shaft to said type carrier.