US2542868A - Detachable platen mounting for typewriting or like machines - Google Patents

Description

1951 H J HART ET AL 2,542,868

DETACHAB LE PLATEN MOUNTING FOR TYPEWRITING OR LIKE MACHINES Filed Jan. 51, 1949 2 Sheets-Sheet l INVENTORS HENRYJI HART BY WILLIAM H. KUPPER Feb. 20, 1951 H. J. HART ET AL DETACHABLE PLATEN MOUNTING FOR TYPEWRITING OR LIKE MACHINES 2 Sheets-Sheet 2 Filed Jan, 31, 1949 Patented Feb. 20, 1951 DETACHABLE PLATEN MOUNTING FOR TYPEWRITING OR LIKE MACHINES Henry J. Hart and William H. Kupper, West Hartford, Conn.,.assignors to Royal Typewriter Company, Inc., New York, N. Y., a corporation of New York Application January 31, 1949, Serial No. 73,802

2 Claims.

This invention relates to a detachable platen mounting for typewriting or like machines.

In using office machines, particularly typewriters, for difierent kindsof work it frequently is desirable to replace a relatively hard platen with a relatively soft platen, or vice versa, according to whether maximum quietness of operation, or maximum manifolding capacity is desired. The average operator is not able to, or will not take the trouble to make such a change unless it can be ,done without usin any appreciable mechanical aptitude.

It has been proposed heretofore to provide a removable platen mounting construction in which one end of the platen is journalled in a support, e. g. a carriage end plate, in such manner that it may be released so as to permit the platen to be tipped or tilted about its other end, and then moved endwise to disengage its other end from its supporting and journalling means, thus enabling a platen having the desired different characteristics to be substituted by a reverse operation. Examples of prior constructions embodying this basic concept are disclosed in the patent to Myers 1,496,940, and Handley 2,028,280.

An object of the present invention is to provide a detachable platen and mounting or supporting means therefor of the general class referred to above, but which is of improved construction enabling the platen to be removed from or inserted in operative position more easily than has been possible heretofore.

A representative construction embodying the invention in a preferred form is illustrated in the accompanying drawings, in which:

Figure 1 is a fragmentary front elevational view, partly in section, of a typewriter carriage and removable platen embodying the invention, the platen being shown in its normal position in dotted lines, and being shown in full lines in the position to which it may be tilted for being removed from the carriage;

Figure 2 is an exploded perspective detail view showing a line-spacing spindle and associated parts;

Figure 3 is a vertical cross section on the line 3--3 of Figure 6;

Figure 4 is a detail fragmentary view, partly in section on the irregular "line 44 of Figure 5, and partly in elevation, drawn on an enlarged scale, showing the right-hand end of the removable platen locked in normal operative position in the carriage;

Figure 5 is a cross section on the line 5--5 of Figure 4; and

Figure 6 is a vertical longitudinal sectional view of the left-hand end of the platen, the associated supporting part of the carriage and linespacing mechanism.

In the drawings illustrating a preferred embodiment of the invention there is shown a typewriter carriage A on which is supported for easy removal and replacement a platen or cylinder B. In most respects the carriage is of standard or well-known construction and includes end plates l and 2 on which the platen is journalled at its opposite ends. The arrangement is such that the right-hand end of the platen may be released from its journal support and tipped upwardly from the normal dotted line position to the full line position shown in Figure 1, and then withdrawn toward the right so as to disassociate the left-hand end of the platen from its journal support on the carriage end plate I.

At its right-hand end the platen is provided with a hub 3 secured to the platen by screws, one of which is shown at l in Figure 4. A stub shaft 5 is secured to the platen hub 3 by set screws 6. The outer end of th stub shaft 5 is equipped with a finger knob I having a hub 8 secured to the shaft 5 by means of set screws 9. Between the platen hub 3 and the knob hub 8 is a bearing sleeve II! in which the platen shaft 5 is freely rotatable. The sleeve [0 is formed with :an exteriorly grooved part II adapted to be received in an open-end seat l2 in the carriage end plate 2, the arrangement being such that the sleeve Il] may be inserted in the seat 12 from above, and removed from the seat by upward swinging movement from the dotted line position to the full line position shown in Figure 1.

Normally the sleeve I0 is held in the position shown in Figure 4 and shown in dotted lines in Fi ure l by a retainer or latch l3. The latch I3 is so constructed and arranged as normallyto maintain the sleeve l0 firmly in its operative position, but so as to be releasable readily for enabling the right-hand end of the platen to be tipped upwardly for removal. In the: form shown, the latch I 3 is pivoted as at M on the carriage end plate 2, and is provided with a finger piece I5 and with a cam face I 6 adapted to engage the sleeve I 0 and press it firmly into its seat 12 when the latch I3 is swung from the position shown in dotted lines in Figure 5 to the position shown in full lines in this figure.

In order that the latch l3 maybe held releasably in its operative or latching position it is provided with a sprin finger detent I7 adapted to engage a fixedpin l8 carried by the end plate 2. Preferably the detent I1 is formed integrally with a shroud I9 secured to the latch I3 by screws passing through slots 2i in the shroud and having threaded engagement with the latch 53. The shroud provides a cover for the platen hub 3, the latch I3 and the inner end of the sleeve I ii, thereby enhancing the appearance of the assembled parts adjacent to the right-hand end of the platen. The mounting of the shroud I9 on the latch I3 by the screw and slot connections 2Il2I enables the detent finger I! to be adjusted so as to determine the latched position of the retainer I3 as that in which the proper pressure will be exerted upon the bearing sleeve ID.

Th left-hand end of the platen is journalled on the carriage end plate I and is operatively associated with line-spacing mechanism by which the platen may be turned through one line space V bearing sleeve 24 extends through the carriage end plate I and has its outer end threaded to receive a nut 25 which cooperates with a shoulder 26 on the sleeve 24 for clamping the sleeve in place. i

A hollow spindle 2I journalled in the sleeve 24 extends outwardly through an opening 28 in the ear 23 and into the hub 29 of a finger knob 30, set screws 3I securing the hub 23 and spindle 2'I infixed assembly. The hub 29 is formed with a reduced part 32 by which the hub is journalled in the opening 28 of the car 23. As will be described later, turning of the knob and the spindle 2! serves to rotate the platen either a line space or a fractional line space as may be desired.

Mounted to turn freely on the spindle 21 and located 'to the right of the bearing sleeve 24 is a line spacing ratchet wheel 33 which is fixed to a line spacer coupling ring 34 to be described in more detail hereinafter.

The ratchet wheel 33 is adapted'to be operated by known mechanism including a combined carriage return and platen line spacing lever (not shown) and connections between the lever and the ratchet wheel 33 including a pawl 35 carried by a rockable lever 36 adapted to be actuated by the line-spacing lever (not shown) for causing the pawl 35 to engage the ratchet wheel 33 and turn it about the platen axis. A selector shield 31 equipped with a finger piece 38 is mounted for adjustment around the ratchet Wheel 33 to enable th operator to select the number of complete line space increments through which the platen is to be turned upon an operation of the line-spacing lever (not shown).

New and improved means are provided for coupling the spindle 27 to the platen B, and for coupling the platen to the line spacing ring 34.

As shown in Figure 6, the left end of the platen B is provided with a hub 39 secured to the platen by screws 40. The hub '39 is formed with an 1 axial opening M, the outer end of which is spindle 2! are centered with respect to each other.

The hub 39 is formed with cylindrical outer end part 43 which receives for sliding movement a disk part 44 to which are fixed three guide pins 4 45 extending through bearings or bushings 45 secured in holes 41 in the platen. Springs 48 positioned in the holes 41 are arranged to press-upon collars 49 respectively on the pins 45 for urging the pins and the disk part 44 toward the left as viewed in Figure 6.

A split ring 55 formed with a finger 5i is spring fitted into an undercut recess 52 in the disk part 44 as best shown in Figures 3 and 6. When the parts are assembled, the ring 55 is fast with the disk part 44 and the finger 5i projects inwardly through a slot 53 in the hub 39 so as to intersect th platen axis.

In order thatthe disk 44 may be operatively coupled to the line -spacing ring 34 in rotational driving relationship, the disk is formed with three circumferentially spaced radial extensions 54 ----54 -54 which are toothed respectively at 55 55 and 55 so as to be engageable with internal teeth 55 on the ring 34. The teeth .55, 55 and 55 are tapered, as best shown in Figure 6, to facilitate movement of the disk 44 from the left of the toothed part 56 of the ring 34 to a position in which the toothed part of the ringsure rounds and is engaged by the teeth on the disk 44.

In order that the disk 44 may be disengaged from the toothed part of the ring 34 when the platen is journalled in its normal position, and in order that the platen may be turned through a fractional line space increment, a rod" or pin 51 is mounted for sliding movements in the hollow spindle 2i and has its inner end arranged "to engage th finger 5| carried by the disk 44 so that the disk may be pushed toward the right in Figure 6 to remove it from engagement with the ring 34. Fixed to the outer end of therod 51 is a finger button 58. A sleeve 59, fixed to the rod 51 adjacent to the button 53, is formed with an external flang 69 which is adapted to engage an internal flange 6| on the knobhub 29 for limiting the outward movement of the rod 51 and the button 58 under the urge of a spring 62 interposed between the button 58 and the left end of the hub 29. Normally the spring 62 holds the button 58 and rod 51 in the position shown in Figure 6 in which the right-hand end of the rod 51 is disengaged from the finger 5| carried by the fractional line spacing disk 44. By pressing the button 58 toward the right, the rod 5'! will be caused to push the finger 5| and the disk 44 to the right to disengage the teeth 55, 55 and 55 from the teeth 56 of the ring 34.

The mechanism for coupling the finger knob and the spindle 21 in rotational driving relationship with the platen B includes a radial arm 53 secured to the inner end portion of the spindle 21 and having its outer end bent to provide a V broad fiat thin tongue 64 extending parallel to the platen axis and toward the end plate 2. The

stantially tangentially to imaginary circles concentric with respect to the spindle axis. When the parts are in the assembled relationship shown in Figure 6 the tongue 64 projects through the general plane of the teeth 55 on the ring 34, and into one of three openings 65, 55 and 35 in the disk 44. The openings are spaced circumferentially from each other and are displaced angularly with respect to the disk extensions 54 54 and 54 so that each opening lies midway between two adjacent disk extensions. show the parts so positioned that the tongue 54.

projects into the disk opening 65*, whereby when the spindle 21 and arm 63 are rotated, the tongue The drawings 64 will drive the diskandhe'nc'e the plate'nro tationally. 1

When it is desired to eifect' only a fractional line spacing movement of the platen, the button 58 is pushed inwardly to disengage the disk M from the ring 34 as described above, enabling the knob ac to turn the platen through the medium of the spindle 27 and the .arm 63 while the line spacing ring 34 and ratchet wheel 33 remain stationary.

A particular advantage provided by the present invention is the ease with which the platen maybe tipped and otherwise manipulated for placing it in or removing it from its normal position. This advantage results more particularly from-the novelformation and arrangement of the holes 65 65 and 65. and the tongue 56. As shown in Figure 3, each of the holes 65*, 65 and 65 is substantially reotangular'and includes two opposed sides which extend parallel to one ananother and substantially or generally radially with respect to the axis of the disk M. These two sides of each hole are so spaced as snugly or closely to engage or embrace the two longitudinally extending edges of the tongue 66. The other two sides of each of the openings et 55 and 55 are mutually opposed and are spaced from each other so as to provide substantially more clearance with respect to the fiat surfaces of the tongue 64 than would be required for accommodating the tongue when the spindle 2? and the platen are axially aligned. In a general way, the inner and outer sides of the openings are tangent to imaginary circles concentric with the axis of the disk 44.

The platen can most easily be placed in its operative position by first turning the spindle 21 to place the tongue 64 above the axis of the spindle 2'! as shown in Figures 1 and 6, and then inserting the tilted platen endwise to the left to the position shown in full lines in Figure l in which the tongue 64 is received by the opening 55 The ample clearance between the broad faces of the tongue 65 and the inner and outer sides of the opening 55 makes it possible for the platen to be inserted in the tilted position, and then swung downwardly to horizontal position without any binding between the tongue 64 and the sides of the disk opening 65 Because of the angularly displaced positions of the openings 65*, 65 and 65 with respect to the disk extensions 54 54 and 5%, each of the openings is disposed diametricall opposite one of the disk extensions. For example, as shown in Figure 4-, the disk opening 55 is diametrically opposite the extension 54. After the platen has been placed in the tilted position with the tongue e4 extending into the opening th and is then tilted, the teeth 55 on the extension 5 t which will move more than any other part of the disk 54 during tipping of the platen to its horizontal position, will extend and move parallel to the adjacent teeth 55 on the ring 34. This will enable the teeth 55*" to be moved into mesh with the adjacent teeth 55 without substantial binding, the tipping of the platen not bringing about any substantial lack of parallelism between the teeth 55 and the adjacent teeth 55. The teeth 55% and 55 on the disk 34 will be somewhat out of parallelism with the adjacent teeth 55 during the tipping movement, but the teeth 55 and 55 are located at or so close to the axis of tipping that the rela tive movement between these teeth and the teeth 56 is small, and no appreciable binding or interference to tipping can be noticed.

The construction illustratedand described herein embodies the invention in a preferred form but it is intended that the disclosure be illustrative rather than definitive of the invention. The invention isdefinedin the claims.

We claim:

1. In a typewriting or likemaohine, a support having spaced end members; a spindle journalled in one of said end members and having an inner end portion projecting towards the other of said end members; a fractional line spacing mechanism including a ringconcentric with and spaced radially from said spindle and formed internally with teeth extending parallel to the spindle axis; an arm fast with said spindle and extending radially outwardly therefrom and having at its outer end a flat broad thin tongue projecting parallel to the spindle axis through the general plane of said ring and towards said other of said end members, and having its broad faces tangent respectively to circles concentric with said spindle a cylindrical platen having at one of its ends means cooperable with said spindle inner end portion for centering said platen end with respect to said spindle; a disk on said platen end having three radial extensions equally spaced circumferentially from each other and having outer toothed portions adapted to mesh wit-h the internal teeth on said ring, said disk also having three openings equally spaced circumferentially from each other and displaced angularly about the disk axis so that there is one such opening angularly midway between each two adjacent disk radial extensions, any one of said openings being adapted to receive said tongue for coupling said spindle to said platen in rotational driving relationship, each of said openings being substantially rectangular and having two opposed substantially radial sides adapted snugly to embrace opposite edges of said tongue, the other two sides of each opening being spaced radially from each other by substantially more clearance than is required for accommodation of said tongue when said spindle and platen are axially aligned; an open end bearing sleeve seat in said other of said end members; a bearing sleeve for journalling the other of said platen ends and being receivable in said seat; and a releasable retainer for holding said sleeve in said seat, releasing of said retainer permitting said platen to be removed from said support by tilting the platen about said one of its ends and then moving it longitudinally of its axis.

2. In a typewriting or like machine, a support having spaced end members; a spindle journalled in one of said end members and having an inner end portion projecting towards the other of said end members; a fractional line spacing mechanism including a ring concentric with and spaced radially from said spindle and formed internally with teeth extending parallel tothe spindle axis; an arm fast with said spindle and extending radially outwardly therefrom and having at its outer end a fiat broad thin tongue projecting parallel to the spindle axis through the general plane of said ring and towards said other of said end members, and having its broad faces tangent respectively to circles concentric with said spindle; a cylindrical platen having at one of its ends means cooperable with said spindle inner end portion for centering said platen end with respeot to said spindle; a disk on said platen end having three radial extensions equally spaced circumferentially from each other and having outer toothed portions adapted to mesh with the internal teeth on said ring, said disk also having three openings equally spaced ciroumferentially from each other and displaced angularly about the disk axis so that there is one such opening angularly midway between each two adjacent disk radial extensions, any one of said openings being adapted to receive said tongue for coupling said spindle to said platen in rotational driving relationship, each of said openings being substantially rectangular and having two opposed substantially radial sides adapted snugly to embrace opposite edges of said tongue, the other two sides of each opening being spaced radially from each other by substantially more clearance than is required for accommodation of said tongue when said spindle and platen are axially aligned; and means journalling the other of said platen ends in said other of said end members in a manner to permit releasing of said other of said platen ends and tilting of said platen to disengage it from said spindle and said tongue.

HENRY J. HART. WILLIAM H. KUPPER.

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

UNITED STATES PATENTS Myers June 10, 1924

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