US2112794A - Typewriting machine - Google Patents

Description

March 29, 1938. B. c. STICKNEY TYIEWRITING MACHINE Filed June 15, 1955 B, C. STICKNEY TYPEWRITING MACHINE March 29, 1938.

5 Sheets Sheet 2 Filed June 15, 1935 m T N E V N March 29, 1938. B. c. STICKNEY TYPEWRITING MACHINE 3 Sheets-Sheet 5 Filed June 15, 1935 W Fig/0.

Patented Mar. 29, 1938 UNITED STATES PATENT OFF TYPEWRITING MACHINE Application June 15,

13 Claims.

This invention relates to adjustable line-spacing mechanism of typewriting machines, in which there are provided two independently-adjustable regulating keys, one of which determines the 5 measurement of the line-space unit, and the other of which determines how many units shall be included in the line-spacing stroke of platen or work-sheet.

The objects of the invention are to produce a 10 simple, inexpensive, reliable and durable mechanism of this class, especially one that can be readily incorporated in machines of standard manufacture.

One feature of the invention is a unit into which the regulating members are built for ready attachment to an Underwood Standard portable typewriting machine.

The extent to which the platen is rotated, by means of the unadjustable platen-driving train, depends wholly upon the compound adjustment of the stationary regulating train. Thus is gained an advantage in eliminating adjustable parts from the driving train, which is capable of rotating the platen to the maximum, while the extent of the platen rotation is minutely variable by the use of the compound regulating train, the latter determining at what point the non-regulatable driving train will become clutched to the linespace wheel. The driving train is normally unclutched from the wheel, so as to permit free rotation of the platen forwardly o-r backwardly.

The regulating train is universally adjustable at one of its ends for obtaining any measurement of line-space unit within the limits of the machine. Said train is also independently adjustable at the other end for determining how many units shall be included in each line-spacing stroke of the platen. All adjustments are confined to a train which is entirely stationary at 40 the line-spacing operation.

There is preferably employed a line-space ratchet-wheel which is connected by movementreducing gearing to drive the platen. This is done for the purpose of using ratchet-teeth of minute pitch, so that there will be numerous teeth included in even the smallest stroke of said ratchet-wheel.

The invention provides for said ratchet-wheel to be driven by a pawl that is pivoted upon an arm (mounted concentrically with the ratchetwheel) driven by the line-space lever, a movement-multiplying train of toothed gearing connecting the line-space lever to thepawl-lever.

One of the aims of the present invention is to provide for a machine of the Underwood class 1935, Serial No. 26,735

an attachment in which compactness is secured mainly by reason of the design of the novel linespacing train. The train includes a forwardlyextending carriage-returning handle, which is mounted illustratively upon the shifting carriage- :5 frame of the Underwood (which shifts up and down to different case-positions).

compactness is reached by mounting both linespace wheel and its driver-arm upon an axis parallel with the platen-axis, and by fixing to the line-space wheel a small pinion which meshes with a large gear provided upon the platen-axle, the line-space Wheel and gearing being very compact, very little space being occupied at the end of the platen. The movement-multiplying connectio-n between the line-space lever and said line-space wheel includes a forwardly and rearwardly moving rack, overlying a pinion and meshing therewith (compactly occupying the same plane as the pinion), said pinion being fixed to or formed upon the hub of said arm that drives the line-space wheel; the forward end of said rack having a knuckle-joint connection with the line-space lever.

Movement of the line-space lever toward the right drives forward said short arm and knuckle, together with the rack, and this drives the underlying pinion forwardly, together with the arm, the pawl and the line-space wheel; and the latter, by means of the pinion and gear, line-spaces the platen rearwardly. The rack, arm, pawl, line-space Wheel and platen-gear, with its pinion, make a compact assemblage that projects but very little beyond the end of the platen-frame, and that permits the entire device to be included in a housing that is readily attached to the end '35 of the shiftable platen-frame or carriage of an Underwood machine.

The driving pawl is normally released, but is automatically clutched instantly to the line-space 40 wheel at any required point; and it is preferably withdrawn from the line-space wheel before making its return stroke.

The pawl clutching and uriclutching member or cam can be adjusted around the line-spacewheel arbor by the use of two adjustments selectively, one of which adjustments includes a forwardly and rearwardly adjustable fulcrum for the lower end of a regulating lever; the other adjustment including a series of fixed notches for engagement by a spring-detent that is carried by the upper end of the regulating lever. Preferably it is only necessary to push the lever forwardly or backwardly to the desired point; the

detent yielding to the push, and snapping into the desired notch.

Said regulating or timing lever is pivoted between its ends to a sliding rack, to which the pawl-releasing cam is geared, and which is thereby adjustable around the axis of the line-space wheel; this adjustment being partly under the control of the means which adjust the leverfulcrum upwardly and downwardly, and partly under the control of said notches and detent.

The fulcrum-pin fits in a slot in the regulating lever, the slot being radial to the point where said lever is pivoted to said rack, with the result that when the regulating lever is swung to the extreme rear, its slot coincides with a fixed diagonal line along which the fulcrum-pin is adjustable by means of an arm. I'his gives the zero position of the line-space regulator.

It will be understood that all drive-strokes of whatever length terminate at the same point, at which point the drive-pawl engages a fixed stop, the latter preventing overthrow of the linespace wheel and platen. In other words, the point of clutch-closing is variable, but the point of ending of the drive-stroke is always the same, because overthrow must be prevented, regardless of the length of stroke. Hence, the pawl must always reach the stop, regardless of the adjustment of the regulating lever, and for this reason the fulcrum-pin may be adjusted to any extent when the lever-slot is in zero position but without stirring the pawl-lever, this position being the unvarying stopping position for the pawl at all drive-strokes.

The pawl is instantly forced into mesh with the platen-rotating ratchet, by means of the power of the line-space lever. For this purpose the pawl is freely pivoted upon an idle arm that is frictionally retarded. The powerdrive is communicated to the pawl to turn it independently on its own pivot and into mesh with the wheel teeth, since the pawl independently is more yieldable than is the retarded idle arm whereon it is pivoted.

This is an improvement onmy application, Serial No. 520,507, filed March 6, 1931 (now Patent No. 2,013,677, dated September 10, 1935).

Other features and advantages will hereinafter appear.

In the accompanying drawings, I

Figure l is a perspective end view of the platen and the line-spacing mechanism, partly broken away, and readily substitutable for the standard mechanism in an Underwood portable typewriting machine. The parts are shown in normal positions.

Figure 2 is a plan showing the conclusion of a line-spacing stroke. 1 V

Figure 3 is a sectional elevation, illustrating the positions atthe conclusion of the line-spacing drive-stroke; the line-space lever and rack being shown in operated or'forward positions, and the platen-driving pawl being shown locked against overthrow.

Figure 4 is a perspective, showing the casing of the line-spacing mechanism and the adjustable parts protruding from said casing and including a regulator set for double-space, and a minute adjuster set for maximum. length of line-spacing unit.

Figure 5 is a perspective of the platen-driving gear train.

Figure 6 is a sectional end elevation of the Underwood portable carriage having the present improvements, the parts being in normal positions; this figure showing the regulating lever, its fulcrum-adjusting means, and its connection tothe timing cam; the top regulator being shown set to give a double line-space movement, and the minute adjuster at the front being shown set for a unit of maximum length.

Figure 7 is a sectional rear elevation of the floating regulating lever, etc.

Figure 8 is a sectional plan of the mechanism seen at Figure 6.

Figure 9 is a sectional plan of parts seen at Figure 7.

Figure 10 is a sectional side elevation of the platen-driving train in its preferred form, showing the platen-driving pawl thrown into clutching engagement by means of power applied to the line-space handle.

Figures 11 and 12 are perspectives of a frictional retarding device and a pawl-carrying arm that is retarded thereby.

Figure 13 is a sectional plan of parts seen at Figure 10.

Figures 14 and 15 show a pawl and an operating arm to vibrate the pawl into mesh with the line-space wheel.

Figure 16 is a perspective of the parts seen at Figure 10.

Figures 17 and 18 are sectional side elevations showing the closing and opening of the clutching mechanism.

The invention is illustrated in the form of a manufacturing unit ready for attachment to the carriage of an Underwood Standard portable typewriter, replacing the regular line-spacing mechanism.

A carriage-return and line-spacing handle I0 extends forwardly from a fulcrum-screw I2. The fulcrum-post is secured upon an ear l3, which is bent inwardly from a boxwork attached to the end of Underwood portable carriage [4. This handle is connected to rotate a platen 15, which has an axle l6 whereby it is journaled at one end in an end (not shown) of the up-and-down shiftable platen-carriage and at the other end in said boxwork, the axle having at its ends the usual handwheels l8.

The platen-driving train includes the lever 10, operating as a bell-crank, with its short terminal arm l9 extending to the left (Figures 1, 8) from the fulcrum I2. In the rack and at the junction of the main and short arms of the lever is a screw post 20, serving as a wrist or knuckle, which thrusts forward a rack 2|; said elbow-lever l0, l9 having a socket 22, in which works a roller 20, provided upon knuckle 20. The socket 22 is widened, as shown, so as to accommodate the lever movement. The knuckle or post is threadedinto the rear end of rack 2|, and provided with lock- Upon its under side the rack 2| has teeth 23 meshing with a pinion segment 24, which is under the rack and indirectly drives a line-space wheel 25. The line-space Wheel is of relatively mammoth diameter and has minutely pitched teeth, to admit of close adjustment of the length of the unit of line-spacing.

It will be noted that the line-space lever III is thus connected to drive said wheel 25 by means of a movement-multiplying train, inasmuch as the diameter of wheel 25 is much greater than that of segment 24. The movement of the gear train is thus multiplied or magnified up to the point where fine line-spacing regulation is effected, namely, at the periphery of the line-space wheel 25; and the relatively great angular movement of the latter is then reduced by means of a pinion 26 fixed thereto and meshing with a large gear 21, the latter fixed to the platen l5, whereby the angular movement of the platen is considerably reduced from that of the line-spacing wheel 25. By this train of movement-reducing gearing the line-spaced movements of the platen are rendered much smaller than the amplified driving movements of line-space pawl 29.

Said line-space wheel 25 and pinions 24 and 26 may be fixed or mounted upon a counter-shaft 28, parallel with the platen-axle; and it will be seen at Figures 1, 4, 5, and 8 that the described gearing, including rack 2|, is highly compacted in a direction longitudinally of the platen, the line-space wheel 25 being facewise to or overlapping the gear 21, and but little spaced therefrom, the pinion 26 being in the same plane with 21, and the rack 2| being in the same plane with pinion 24, the latter being close to the line-space wheel 25.

It will be seen that the typewriter-carriage is not unduly lengthened, since the described mechanism, together with other features hereinafter detailed, needs not to protrude farther to the left from the platen-frame ends (not shown) than does the usual platen-controlling mechanism in the Underwood desk machine{ the present improvements being substitutable for ordinary platen releasing and controlling mechanism, in either small portable or large standard desk machines.

The line-space wheel is driven by a clutch in the form of pawl 29, which is pivotally mounted at 30 upon the end of drive-arm 3|, which turns concentrically with the line-space wheel to drive the same, being for this purpose fixed to the driving pinion 24, which is preferably in the form of a segment formed upon the hub end of said driving arm 3|. The segment is sufficient, inasmuch as the stroke of the arm 3| is less than a full revolution. Forming of the teeth thus upon the arm-hub conduces to compactness, since the arm lies in the same plane as the pinion, and adds nothing to the length of the typewriter-carriage. The arm swings alongside of the line-space wheel 25, and the pawl projects towards the right from said arm, overhanging the wheel as at Figures 5, 8, 13. The wheel 25 may in some cases have a surface movement of as much as one and threequarters or two inches, in effecting maximum movement of the platen, which is about half an inch.

The movement produced by lever I is thus amplified so as to give pawl 29 a long stroke, to permit the use of numerous teeth in the small compass of a line-space drive of the pawl, so that an error of a single tooth would be so small, when compared with the great number of teeth in a line-space-Wheel movement, that such error may be negligible. The device provides practically a universal clutch between the lever l0 and the platen l 5. The reason for making the line-space wheel of mammoth diameter and providing it with very minute teeth is that it may be rotated to the desired maximum by means of the lever l9, l9, thereby securing this negligibility without the necessity of providing a train of toothed gearwheels between line-space lever and line-space wheel. This amplified movement of pawl and wheel is compensated for by the use of the movement-reducing train to the platen. Owing to the fineness of the pitch of the teeth, sufliciently accurate spacingof the platen is secured for all kinds of adjustments of stroke of the line-spacing mechanism.

The line-space lever may have the usual length of stroke. The arrest of handle 'l 0, pawl-carrying arm 3| and platen may be effected by means of an overthrow-stop 33,.which is in the form of a lug bent in from the boxwork, or fixed to the platen-frame in position to intercept the pawl 29; the latter having a beveled edge, as at 35, which engages said stop, whereby the pawl is wedged into the teeth of the line-space wheel, locking the same, and overthrow thereof is .prevented; the conclusion of the line-space stroke being seen at Figures 3 and 18.

If it is desired, to avoid undue straining of the drive-train at the arrest of the platen, the rack 2| may be provided with a rear slide block 36, to work in a fixed guide slot 36 and engage a stop 3'! formed by the forward end of the slot.

The multiple toothed pawl 29 is swung quickly into mesh with the line-space wheel 25 at the beginning of the drive-stroke of the handle ID, by means of spring 56, Figure 17.

This meshing movement of the pawl is under the control of a line-space regulating trip or cam 52, which is universally adjustable about the counter-shaft 28 and permits the clutch 29 to close at the proper point under the tension of said spring 56. This cam 52 is a cast-off device, and lies in the path of releasing shoulder 54 that is formed upon the pawl. The cam 52 lies in such path so as to be encountered by the shoulder upon the return stroke of the linespace train that is effected by main returning spring 54 whereby the pawl is fended away fromthe line-space ratchet-wheel 25, Figures 6 and 10.

As will hereinafter appear, by adjusting the cam 52, the release of the pawl 29 and its reengagement with the wheel 25 upon the succeeding operation, may be properly timed throughout all of the variations in the measurement of the line-space unit which are securable by the novel line-space-regulating train. This train has separate adjustments. It is capable of one kind of adjustment for determining how many line-space units shall compose the line-feeding stroke of the platen, and it is also capable of a diiferent and independent adjustment for'varying minutely the length of such line-space unit.

Included in the line-space-regulating mechanism is means for mounting said trip or cam 52, so that it can be set rotatably to different positions about the counter-shaft 28. Such adjustment is concentric with the movement of the pawl-carrying arm 3|, whereby the cam may be swung around to different points in the path of the shoulder 54 of the returning drive-pawl; so that the pawl 29 (which may ride freely back over the teeth of the line-space wheel 25) will be clutched to said wheel at the desired point at the next drive-stroke. Thus the length of driveof the wheel and the extent of the line-space move ment of the platen may be predetermined or measured.

Means is provided for effecting adjustment at each end of a space-regulating lever 43 independently of the other end. One adjustment (at the bottom end of the lever) determines the measurement of the line-space unit. The other of the adjustments (at the top of the lever 43) determines through how many of such units the platen shall be rotated at each stroke -of the carriage-returning lever 10. Each of said adjustments of lever 43 is independent of the other.

The line-space-regulating mechanism therefore includes two features. The first feature employs a finger-piece 42 provided upon vertical lever .43 rising above the top 44 of the boxwoik casing; said lever being of the second order andprojecting up through a slot 45 in said casing. The slot'is provided in one side with spaced notches 46, for detaining the lever in any one of several predetermined positions. The lever has a spring-detent 41 (Figures 5, 6, and 8) of V shape, adapted to snap into any of the notches 46, to hold the regulator 43 in position for obtaining either 1, 1 1 1%, or 2 units of linespacing, at each line-feed of the platen and paper.

This floating lever 43 hasa longitudinally slotted lower arm co-acting with a shiftable fulcrum in the form of a stud 48, and between its ends said floating lever is pivotedat 49 to a rack 50. The rack has teeth 5|] upon its upper edge, and works forwardly and backwardly below a segment 5|, being in mesh therewith; whereby the segment may be rotated, together with said timing cam or disk 52, which is loose upon countershaft 28.

Said timing disk 52 is stationary at the linespacing operation, but is rotatively and delicately adjustable to vary the timing of the clutch which drives the platen; or, in other words, to vary the point at which the driving pawl 29 is let into engagement with the line-space wheel 25,'and hence to determine the length of the line-space unit.

The disk 52 has a circular edge 53, forming a dwell, upon which rides said releasing or timing shoulder 54 that is provided upon the driving pawl 29. As long as said shoulder or projection 54 rests upon and rides along the circular dwell 53, the pawl is kept out of mesh with the line-spacing wheel 25, as at Figure 6; but at a point which is determined by the previous rotative setting of the cast-off timing disk 52, the pawl 29 is permitted to drop into mesh with the wheel 25, and hence the platen is rotated dur ing the remainder of the drive-stroke of the line-space handle I0.

Upon the return stroke of said handle Ill, effected by spring 54 the line-space pawl 29 at first rides idly back over the teeth of the linespace wheel 25, and the pawl is then withdrawn therefrom by its shoulder 54 coming into engagement with a cam or bevel 55 that is provided upon the end of the segmental dwell 53. During the remainder of the return stroke of the line-space handle ID, the timing projection 54 rides idly upon the dwell 53. It also rides idly thereon at the first part of the next succeeding drive-stroke of the handle, until the pawl reaches the shoulder 55, whereupon the spring 56 snaps the pawl into mesh with the line-space wheel to drive the same.

The segment 5| may have an angular range sufilcient to be able to turn the timing disk 52 through about one-half of a revolution, or a little over; unnecessary teeth of 5| being cut away, to afford clearance for the rack slide when this slide is adjusted towards'the rear, thus further conducing to compactness.

The timing rack 50 is supported and confined at its rear end by means of a headed stud 59, under the shaft 28, and slides forwardly and backwardly'. The stud 48 projects out through a horizontal guiding groove 60 in wall 63 of the boxwork frame. At its forward end the rack is supportedand guided by said stud. Its upper rear guide is the pinion 5|, and its lower rear guide and support is the headed stud which confines the rack against the innerface. of the vertical bracket-wall 63. The lever 43 is carried upon the stud or pin 49, which is: guided back and forth in the horizontal slot 60.

The downwardly extending radial slot 63 in the floating lever 43, permits upward shifting of its fulcrum stud 48. The latter projects from a microscopic regulator in the form of a lever 53*, having a slotted rear end mounted upon a fixed stud or support 63, and havingat its forward end a finger-piece 63 When the fulcrum-pin 48 is at its lowest location, the length of each line-space unit will be say one-sixth of an inch. When said fulcrumpin 48 is adjusted to its top position, the linespace unit measurement will be about one-ninth of an inch. Graduations H, Figure 4, for the lever index H may be numbered accordingly, to indicate six, seven, eight or nine spacing units to the inch, with fractional graduations if desired.

It will be understood from Figure 6 that when the fulcrum-pin 48 is adjusted upwardly along a diagonal slot 66, in the fixed wall 83, the fulcrum-pin 48 will have a camrning effect upon an edge of the slot 63 and will thereby swing the line-space regulating lever 43 about a point where its spring-detent 41 rests in a notch 46 formed in the table 44. The moving rack 50 will gradually cause pinion 5i and cam 52 to swing around the counter-shaft 28, thereby adjusting the cam, whereby it may be set for a shorter line-space unit. To secure a minimum line-space unit, adjustment of the fulcrum-pin 48 is continued to the extreme upper ends of the guideslots 63 68. By setting the gage-lever 63 down, the line-space unit may be lengthened.

The adjustment of the fulcrum-pin 48 is only for the purpose of effecting minute variations in the measurement of the line-space unit, and for this purpose it is universally adjustable regardless of which one of the regulating notches 46 may be occupied by the detent 41 upon the regulator-lever 43.

The notches 46 may be formed at measured intervals to equal one, one and a quarter, one and a half, one and three-quarters or two units, regardless of the measurement of the spacing unit itself. During this adjustment of the lever 43, it swings about the fulcrum pin 48 wherever the latter may have been adjusted, and the effect of the movement of the lever 43 is to adjust the cam-frame 52 to a new setting around the counter-shaft 28. It is only necessary to press the finger-piece 42 forwardly or backwardly, and it may be left in any desired notch, the notches being appropriately ntu'nbered. Lever 43 is thinned at 66 to render it flexible. It snaps into the notches by reason of its resiliency.

The diagonal slot 66 is coincident with the lever-slot 63 when the lever 43 is swung rearwardly to a zero position, that is, when the cam 52 is in position to encounter the pawl-shoulder 54 as the latter is at or close to the end of its drive stroke. When the slot (53 is in such position, it will be seen that the fulcrum-pin 48 might be adjusted along the slots without stirring the regulator lever 43.

It is desired that at the end of every drive stroke, regardless of the adjustment of 48, the pawl-head shall engage the lock-stop 33. In other words, the return stroke of the pawl may terminate at variable points, but its drive stroke ends always at the same point, as at Figure 3. The fixed guide-slot line 66 coincides with the position of the slot 63 (radial 13049) when the regulator lever 43 is swung rearwardly to the limit.

It will be observed that the swinging camcarrying frame is regulated by means of a lever pivoted between its ends, and independent adjustments being provided at said lever-ends, in combination with a driving pawl that is mounted upon an arm that is pivoted concentrically with said cam and with the ratchet-wheel, and is directly operable by the non-adjustable linespace lever I having a fixed fulcrum and swinging in a much smaller arc than pawl-arm (H.

The lever 43 may be swung forwardly and backwardly upon the fulcrum-pin 48, to adjust the timing rack 50, together with its pinion I, thus minutely rotating the timing cam 52, to give any length of spacing unit from minimum to maximum.

The position of the timing cam may be varied and the lever 43 may also be set in any of the notches 46, so as to space the platen to the extent of one or more units, to whatever length the unit may have been adjusted by means of gage 63 The effective length of said lever 43 may be shortened by raising the fulcrum-pin 48 upwardly along the slots 66, 63*. For this purpose the finger-piece 63 lifts the pin-carrying arm 63; said index 1| cooperating with scale II, to indicate the number of line-spacing units to an inch. This finger-piece 63 is pivoted upon an arm 12 which is mounted upon stud 48, the latter being guided in a slot 66 in fixed wall 63.

The platen may be rotated by the usual knob- (one at each end of the platen-axle) or by means of a separate finger-wheel 81, the latter being connected by the aforesaid train of movementreducing gearing to the platen, so that the platen may be rotated very gradually under the control of said wheel 81. The movement-reducing train includes the pinion 26 and gear 21; said wheel 81 being screwed upon the outer end of the counter-shaft 28 which carries said pinion 26 and line-space wheel 25.

The preferred manner of forming the pawl and operating it by the segment 24 is illustrated at Figures to 18. The pawl is pivoted at 30 upon an idle arm I00; but the segment is formed upon a drive-arm IOI. Each arm is loosely mounted upon the counter-shaft 28. The drive-arm IOI is loosely confined between the idle arm I00 and a collar I02, which forms the end portion of an elbow-flange I03 bent from the idle arm I00, as seen at Figure 12. The platen-rotation is effected by power transmitted from the segmentarm' IOI directly to the pawl 29. The loose arm I 00 supports the pawl. Drive-arm IOI has a beak I04 which fits loosely in a notch I05 formed in the hub of pawl 29. Therefore when the segment-arm IOI is driven, the beak I04 tends to swing the pawl upon its pivot 30, independently of idle arm I00.

Assuming that the segment 24 is being driven in clockwise direction at Figure 10, the powerarm IOI tends to rock the pawl 29 independently upon its own pivot 30, toward the line-space ratchet-wheel 25. This tendency is increased by the pawl-spring 56. During the first part of the power stroke of arm ID], the trip-shoulder 54 of the traveling pawl rides upon the edge of the disk 52; but when said shoulder escapes or rides off from the rounded end of said disk at 55, the pawl 29 is instantly swung counterclockwise about its pivot 30 into mesh with the teeth of wheel 25, to drive the same,

The closing or clutching movement of pawl 29 is effected partly by the spring 56, and partly by the action of power-arm IOI to swing the pawl independently counterclockwise about the pawlpivot 30.

Moreover, there is no resistance to this independent movement of the pawl, whereas there is considerable drag of the idle pawl-carrying arm I00, so that it is easier for the drive-arm IOI to rock the pawl about its own pivot than it is for said arm to overcome the retarding effect of friction fingers I06 upon the movement of the idle arm I00 to which the pawl ispivoted.

The friction fingers I06 press against opposite sides of a groove I 0'! formed in a hub I08 of the idle arm I00, and tend always to hold said arm I00 stationary (Figure 13); and this drag upon the motion of idle arm I00 has the effect of enabling the drive-arm IN to rock the pawl independently upon its own pivot 30 when the trip-shoulder 54 escapes from the cam-edge 53. This prevents slipping of the pawl-teeth 29 idly over the tips of the teeth of wheel 25, and assures pro-per mesh of the pawl with the wheel.

Thus, the segment 24 primarily rocks the pawl 29 independently upon its pivot, into mesh with wheel 25, and thereupon carries the arm I00 and the wheel 25 as a unit in clockwise direction at Figure 10, against the retardation effected by the stationary fingers I06 that bear in the friction-groove I01.

At the return stroke of the line-spacing handle I0, the drive-arm IOI is moved counterclockwise at Figure 10, and rocks the pawl 29 clockwise about its pivot 30, to take it out of mesh with the wheel 25. This releasing movement of the pawl 29 is limited by a stop I09, that is formed upon drive-arm ml and stops against the inner face of the elbow-flange I03 as seen at Figure 10. At the start of the return stroke of the linespacing lever I0, the pawl 29 is independently swung out of mesh with the wheel 25 at the beginning of the stroke, so that the pawl will not ride upon the wheel teeth, and quietness of operation is therefore obtained. At the conclusion of the return stroke of handle I0, the spring 56 may restore the trip-shoulder 54 of the pawl into re-engagement with the cam-edge of disk 52.

The pinion 26 may be made of one piece with the shaft 28, and the line-space ratchet-wheel 25 may be riveted to the pinion-portion. This pinion-shaft 28 including the line-space-regulating disk 52, the drive-arm 3| and feed-pawl 29 are at one end mounted in the wall 63 formed by the boxwork. The inner end is mounted in a removable bracket-piece III. Thus the parts mounted upon the shaft 28 can be easily assembled as a unit in the boxwork and are accessible and may be removed when desired.

The line-space slide is guided at the rear in the slot 36 and at the front end in a guide-bracket II2 fastened to wall 63.

The novel line-spacing mechanism is compact and fits intothe usual space II 3 (indicated in dot-dash lines at Figures 6 and 7) provided in the Underwood Standard portable typewriter-carrying case.

The friction fingers I06 are shown in Figures 10 and 16 to be fastened by screws II4 to the under side of the top wall 44. f

Variations may be restorted to within the scope of the invention and portions of the improvements may be used without others. 0

Having thus described. my invention,I claim:

1. In a line-spacing mechanism, the combination of a platen, a line-spacing ratchet-wheel connected thereto by movement-reducing gearing, a line-spacing handle, a movement-multiplying driving arm which is driven by said line-spacing handle, an idle arm having a driving pawl pivoted thereon for movement into mesh with said line-spacing wheel, a line-spacing regulator, and means co-operative with said regulator and adjustable for minutely varying the extent of linespace movement of the platen, said pawl having a releasing shoulder, and the regulator having a cam in the return path of said shoulder, said driving arm directly engaging the pawl to slide the pawl along said cam and then to turn the pawl independently upon the pivot off from the end of said cam and into mesh with said ratchetwheel, to prevent the pawl from jumping or skittering over the wheel-teeth, said idle arm and said driving arm being pivoted concentrically with the ratchet-wheel, said cam being settable by said regulator to regulate minutely the point of release, thereby controlling the length of the linespacing movement, and said cam having a segmental dwell-portion to maintain the release of said pawl during the remainder of the return stroke and the beginning of the drive stroke of the linespacing handle.

2, In a line-spacing mechanism, the combination of a platen, a line-spacing ratchet-wheel connected thereto by movement-reducing gearing, a line-spacing handle, a movement-multiplying driving arm which is driven by said line-spacing handle, an idle arm having a driving pawl pivoted thereon for movement into mesh with said line-spacing wheel, a line-spacing regulator, means co-operative with said regulator and adjustable for minutely varying the extent of linespace movement of the platen, said pawl having a releasing shoulder, and the regulator having a cam in the return path of said shoulder, said driving arm directly engaging the pawl to slide the pawl along said cam and then to turn the pawl independently upon its pivot off from the end of said cam and into mesh with said ratchet-wheel, to prevent lthe pawl jumping or skittering over the wheel-teeth, said idle arm and said driving.

arm being pivoted concentrically with the ratchet-wheel, said cam being settable'by said regulator to regulate minutely the point of release, thereby controlling the length of the linespacing movement, and said cam having a segmental dwell-portion to maintain the release of said pawl during the remainder of the return stroke and the beginning of the drive stroke of the line-spacing handle, and means tending to retard said idle arm at the line-spacing operation, to facilitate the independent turning movement of the pawl into engagement with the ratchet-wheel.

3. In a line-spacing mechanism, the combination of a platen, a line-spacing pawl, a linespacing ratchet-wheel having minute teeth, movement-reducing gearing connecting the ratchetwheel to the platen, an idle arm having saidpawl pivoted thereon for movement into mesh with said line-spacing wheel, a line-spacing regulator, means co-operative with said regulator and adjustable for minutely varying the extent of linespace movement of the platen, said pawl having a releasing shoulder, and the regulator having a cam in the path of said shoulder, a driving arm directly engaging the pawl to slide the pawl along said cam and then to turn the pawl independently upon its pivot into meshv with said ratchet-wheel to drive the same, to prevent the pawl from jumping or skittering over. the (DWI-teeth, said cam being settable by said regulator to regulate minutely the point of release, said cam having a dwell-portion to maintain the release of said pawl, and means tending to retard said idle arm at the line-spacing operation, to insure the independent turning movement of the pawl into engagement with the ratchet-wheel.

, l. In a line-spacing mechanism for a platen provided with an axle, the combination of a linespace measuring wheel having teeth of minute pitch, said wheel carried by a counter-shaft which is parallel with the platen-axle, a pawl-driving arm mounted to turn about said counter-shaft, a driving pawl to mesh with the teeth of said line"- space wheel, an adjustable line-space measuring cam upon which saidpawl slides, a small pinion driven by said line-space wheel, a large gear connected to the platen-axle and meshing with said pinion for driving the platen, a line-space lever, a movement-multiplying connection between said line-space lever and said pawl-driving arm, andskittering-preventing means including an idle arm pivotally supporting said pawl, to slide the pawl along the measuring cam, and means tending to retard said idle arm, whereby said pawldriving arm is rendered effective to turn the pawl independently off from the cam and into mesh with the line-space wheel.

5. In a line-spacing mechanism for a platen provided with an axle, the combination of a linespace wheel having teeth of minute pitch, said wheel carried by a counter-shaft which is parallel with the platen-axle, an arm mounted to turn about said counter-shaft and having a driving pawl to mesh with the teeth of said line-space wheel, a small pinion driven by said line-space wheel, a large gear connected to the platen-axle and meshing with said pinion for driving the platen, a forwardly-extending line-space lever having at its rear end a short elbow fulcrurned at its tip, a forwardly and rearwardly moving rack pivotally connected to said line-space lever at the bend of the elbow, and a pinion-device provided upon the hub-portion of said arm and meshing with said rack to be operated thereby.

6. In a line-spacing mechanism for a platen provided with an axle, the combination of a linespace wheel having teeth of minute pitch, said wheel carried by a counter-shaft which is parallel with the platen-axle, an arm mounted to' turn about said counter-shaft and having a normally disengaged driving pawl to mesh with the teeth of said line-space wheel, a small pinion driven by said line-space wheel, a large gear connected to the platen-axle and meshing with said pinion for driving the platen, a line-spaced lever, a movement-multiplying connection between said line-space lever and said pawl-arm, a timing cam mounted upon said counter-shaft, said pawl having a releasing shoulder to ride upon said timing cam, the latter being concentric with the counter-shaft and holding the pawl out of engagement with the line-space wheel during the idling of the pawl, said cam terminating in a portion engageable by said pawl-shoulder for lifting the pawl out of mesh with the line-space wheel, and means driven by said line-space lever for snapping the pawl off from the end of the cam and into mesh with the line-space wheel to advance the same.

7. In a line-spacing mechanism for a platen provided with an axle, the combination of a linespace wheel having teeth of minute pitch, said wheel carried by a counter-shaft which is parallel with the platen-axle, an arm mounted to turn about said counter-shaft and having a driving pawl to mesh with the teeth of said linespace wheel, a small pinion driven by said linespace wheel, a large gear connected to the platenaxle and meshing with said pinion for driving the platen, a line-space lever, a movement-multiplying connection between said line-space lever and said pawl-arm, a timing cam mounted upon said counter-shaft, said pawl having aprojection to ride upon said timing cam, the latter being concentric with the counter-shaft and holding the pawl out of engagement with the line-space wheel during the idling of the pawl, said cam terminating in a portion engageable by said pawlprojection for lifting the pawl out of mesh with the line-space Wheel, and means movable relatively to said pawl-arm and operated by said linespace lever at the line-spacing stroke thereof for snapping the pawl into mesh with the line space wheel when the pawl rides off from said timing cam.

8. In a line-spacing mechanism for a platen provided with an axle, the combination of a linespace wheel having teeth of minute pitch, said wheel carried by a counter-shaft which is parallel with the platen-axle, an arm mounted to turn about said counter-shaft and having a driving pawl to mesh with the teeth of said linespace wheel, a small pinion driven by said linespace wheel, a large gear connected to the platenaxle and meshing with said pinion for driving the platen, a line-space lever, a movement-multiplying connection between said line-space lever and said pawl-arm, a timing cam for controlling said pawl, a timing lever for adjusting said cam to predetermine the point in which the pawl shall drop into mesh with the line-space wheel; said lever being of the second order, and fulcrumed at its lower end, and having at its upper end means for setting it at any one of a series of fixed stations, a rack being pivoted to said lever between the ends of the latter, a pinion fixed to said timing cam and meshing with said rack, said rack extending forwardly and rearwardly, means for guiding and supporting said rack, and a manually-adjustable mount in the form of a lever carrying said fulcrum up and down.

9. In a line-spacing mechanism for a platen provided with an axle, the combination of a linespace wheel having teeth of minute pitch, said wheel carried by a counter-shaft which is parallel with the platen-axle, an arm mounted to turn about said counter-shaft and having a driving pawl to mesh with the teeth of said line-space wheel, a small pinion driven by said line-space wheel, a large gear connected to the platen-axle and meshing with said pinion for driving the platen, a line-space lever, a movement-multiplying connection between said line-space lever and said pawl-arm, a timing cam mounted upon said counter-shaft, means for rotating said timing cam for adjustment, including a lever of the second order having a finger-piece and detent' at its upper end, a device having a series of spaced notches being provided for engagement with said detent, said cam-rotating lever being adjustably fulcrumed at its lower end upon a mount having the form of a manually-adjustable lever, a rack pivoted to the cam-rotating lever between its ends, and a pinion-device meshing with said rack and connected to drive said timing cam.

10. In a line-spacing mechanism for a platen provided with an axle, the combination of a linespace wheel having teeth of minute pitch, said wheel carried by a counter-shaft which is parallel with the platen-axle, anarm mounted to turn about said counter-shaft and having a driving pawl to mesh with the teeth of said line-space Wheel, a small pinion driven by said line-space wheel, a large gear connected to the platen-axle and meshing with said pinion for driving the platen, a line-space lever, a movement-multiplying connection between said line-space lever and said pawl-arm, a timing cam for controlling said pawl, a timing lever for adjusting said cam to predetermine the point in which the pawl shall drop into mesh with the line-space wheel; said lever being of the second order, and fulcrumed at its lower end, and having at its upper end means for setting it at any one of a series of fixed stations, a rack being pivoted to said lever between the ends of the latter, a pinion fixed to said timing cam and meshing with said rack, said rack extending forwardly and rearwardly, a fixed support having an inclined slot, said lever having at its lower end a fulcrum-pin adjustable along said slot, and means for adjusting said pin along the slot, said adjusting means in the form of a loosely mounted finger-lever carried upon said support and forming a mount for said fulcrum.

11. In a line-spacing mechanism, the combination of a platen, a line-spacing wheel connected thereto by movement-reducing gearing, and having minute teeth, a line-space handle, a movement-multiplying arm which is driven by said line-space handle, the latter having a driving pawl for said line-space wheel, said pawlarm being pivoted to turn about the axis of the line-space Wheel, a regulating lever having a fulcrum, and means co-operative with said fulcrum and adjustable independently of said line-space handle for varying the extent of line-space movement, said pawl having a projection, and a releasing cam in the path thereof, said cam being settable by said lever to regulate the length of the line-spacing movement, and having a segmental portion to maintain the pawl released during the remainder of the return stroke of the pawl-arm, means being provided to enable said arm to prevent skittering of said pawl by turning said pawl independently into mesh with said wheel during the drive stroke of the pawl.

12. The combination of a line-space wheel having teeth of minute pitch, a pawl therefor, a driver mounted to swing about the axis of said wheel for driving said pawl, means to operate said driver, a stop to arrest said pawl and linespace wheel, an arm adjustable about the axis of said wheel and having a segmental cam for intercepting said pawl to release it upon the return stroke of said driver and to maintain the pawl released during the further return movement of said driver, a regulating lever pivoted to said releasing arm, a lever-fulcrum adjustable independently of said driver-operating means, for varying the leverage upon said arm, and means to enable said driver to act upon said pawl to force it into mesh with said wheel, to prevent the pawl from jumping or skittering.

13. The combination of a platen, a line-space wheel having teeth of minute pitch, a movementreducing train connecting the Wheel to the platen, a pawl, a driver mounted to swing about the axis of said wheel for driving said pawl and wheel, means to operate said driver in line-space and return strokes, an overthrow-stop to arrest said pawl and line-space wheel, an adjustable cam for intercepting said pawl to release it upon the redwell in a line-space stroke, and a device effective, as the pawl leaves said dwell, to enable the driver to act on said pawl to force the pawl positively into engagement with the Wheel to drive the same, to prevent jumping or'skittering 5 of the pawl upon the wheel.

BURNHAM C. STICKNEY.

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