US1926178A

US1926178A - Variable spacer feed mechanism for typewriting machines

Info

Publication number: US1926178A
Application number: US645073A
Authority: US
Inventors: Robinson Rochfort Wybrants
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-11-30
Filing date: 1932-11-30
Publication date: 1933-09-12
Anticipated expiration: 1950-09-12

Description

Sept. 12, 1933. R. w. ROBINSON 1,926,178

VARIABLE SPACER FEED MECHANISM FOR TYPEWRI'IIING MACHINES Filed Nov. 30, 1932 4 Sheets-Sheet l R. WRobinSra, m4, 4210M Se t. 12, 1933. R. w. ROBINSON 1,926,178

VARIABLE SPACER FEED MECHANISM FOR TYPEWRITING MACHINES 4 Sheets-Sheet 2 Filed Nov. 30, 1952 Spt. 12, 1933- R. w. ROBINSON VARIABLE SIACER FEED MECHANISM FOR TYPEWRITING MACHINES Filed Nov. 30, 1932 4 Sheets-Sheet 3 R. WRo binsofl;

Sept. 12, 1933. R w, 'N 1,926,178

VARIABLE SPACER FEED MECHANISM FOR TYPEWRITING MACHINES Filed Nov. 30, 1932 4 Sheets-Sheet 4 GUM/MA Patented $ept, l2, 193$ UNITED STATEfi that VARTIAELE SPACER FRIED MECHANISM ll filiiliit TWEWRITHNG MACHINES Rochfort Wybrants Robinson, San Antonio, Tex. Application November 341), 1932 15 Claims.

This invention relates to variable spacing feed mechanisms for typewriting machines, and has particular reference to certain desirable improvements in variable spacing feed mechanisms of the type described and claimed in my prior patent, No. 1,712,904.

According to the construction illustrated, de-' scribed and claimed in my aforesaid prior patent the escapement mechanism which controls advance of the carriage in response to depression of the typewriter keys is inclusive of a ratchet bar which is mounted on the carriage for longitudinal movement relatively thereto, whereby the step-by-step advance movement of the carriage may be variably increased relative to the step-by-step advance movements of the ratchet bar so that in copying from a previously typed sheet, lines which are shorter than normal may be lengthened to or approximately to normal line length thus to obtain a uniform margin at the right hand side of the sheet. The mechanism whereby greater advance movement of the carriage than of the rack bar is effected comprises, according to my prior patent, an angularly adjustable track element extending longitudinally of the typewriter, and a bell crank lever pivoted to the carriage and having one of its arms operatively engaged with the rack bar and its other arm equipped with a roller cooperating with the track element. Thus, due to the carriage and, with it, the bell crank, being urged as usual constantly in a left hand direction, and due to the ratchet bar being re-" strained by the escapement mechanism so that the carriage tends constantly to move to the left relative to the rack bar, it follows that the bell-crank reacts from the track element to control advance movement of the carriage relatively to the ratchet bar and that, therefore, the amount that the carriage advances during each step of advance of the ratchet bar is directly dependent upon the angularity of the track element. In other words, if the track element is vdisposed parallel to the path of movement of the carriage the latter obviously will partake of advance movements which are equal-to.advance movements of the ratchet bar. On the other hand, if the track element is disposed at an inclination outwardly relative to the path of movement of the carriage and in the direction of advance movement thereof, then obviously the carriage will partake of advance movements which are greater than the advance movements of the ratchet bar by amounts which are dependent upon the angularity of the track ele-- ment. Now in this connection it is apparent that when the track element is disposed at an inclination relative to the path of movement of the carriage, pivotal movement of the bell-crank lever occurs as the carriage advances with con- 0 sequent shifting of the point of contact of the roller with the track element longitudinally along the carriage in the direction of advance thereof, which results in progressive gain in the advance movement of the carriage relative to. the ratchet bar. This gain in movement of the carriage relative to the ratchet bar due to pivoting of the bell-crank lever, and which increases with increase in the inclination of the track element is not serious if the lines being copied are of approximately equal length, as the resulting slight difference in the length of the typed lines would hardly be noticeable or objectionable. When, however, a comparatively short line is to be copied and made of the same length as other lines, the inclination of the track element may necessarily be so great as to permit considerable pivotal movement of the bellcrank lever, and under these conditions the gain in the advance movement of the carriage relative to the rack bar would result in such excessive lengthening of the copied short line as to be seriously objectionable. Accordingly, one of the important objects of the present invention is to provide, in. a variable spacing feed mechanism of the general type disclosed in my aforesaid patent, simple means whereby any longitudinal shifting of the track element contacting point of the track follower relative to the carriage is avoided. despite pivotal movements of the bellcrank through which said track follower is operatively connected to the carriage and the rack bar or its equivalent, thus to avoid the disadvantages mentioned.

Another important object of the present invention is to provide an improved switch device for rendering the variable spacing feed mechanism selectively operative and inoperalive. In this connection, according to my prior patent, the switch device can be actuated to render thevariable spacing feed mechanism inoperative only when the carriage is in, or subginning of a line to be typed, the said variable spacing feed'mechanism is rendered inoperative.

Certain types of typewriters employ as a part of their escapement mechanism a carriage carried rack or ratchet bar which does not move vertically or laterally relative to .the carriage, while other types of typewriters employ equivalent rack or ratchet bars which are elevated when the typing of a line has been completed to allow the carriage to be returned to its starting position. Therefore, another important object of the invention is to provide a variable spacing feed mechanism which may be embodied with equal facility and which will operate equally as efficiently in typewriters having escapement mechanisms of either type.

Another object of the invention is to provide for adjustments of the variable spacing feed mechanism to facilitate its proper cooperation with any particular typewriting machine in which it may be embodied.

With the foregoing and various other objects in view, which will become more fully apparent as the nature of the invention is better understood, the same consists in the novel features of construction, combination and arrangement of. parts as will be hereinafter more fully described, illustrated in the accompanying drawings, and defined in the appended claims.

In the drawings, wherein like characters of reference denote corresponding parts in the different views:--

Figure 1 is a perspective view looking towards the rear of a typewriting machine equipped with a variable spacing feed mechanism constructed in accordance with one practical embodiment of the invention.

Figure 2 is a view similar to Figure 1 with parts removed to disclose other parts which ar hidden in Fig. 1.

Figure 3 is a bottom plan view showing particularly the present track element follower and its cooperating bell crank, together with the switch mechanism, and illustrating an operative status of the difierent parts.

Figure 4 is a perspective view illustrating an inoperative status of theparts shown in Fig. 3.

Figure 5 is a longitudinal section looking rearwardly and illustrating the relationship between the typewriter carriage and the typewriter frame carried elementsof the variable spacing feed mechanism.

Figure 5 is a view similar to Fig. 5 illustrating the carriage carried elements of the mechanismin the position they occupy when the carriage is in the position it occupies at the beginning of a line to be typed.

Figure 6 is a section on the line 6--6 of Figure 3.

Figure 7 is an end view, partly in section, of the elements shown in Fig. 8.

Figure 8 is a diagrammatic top plan view illustrating the cooperation between track follower and the track.

Figure 9 is a diagrammatic bottom plan view illustrating the cooperation between the track follower and the track. Figure 10 is a view similar to Fig. 9 illustrat ing the relationship between the track follower and the track when the latter is disposed at an inclination to the path of movement of the carriage.

Figure 11 is a rear elevation of the switch lever mechanism showing the status of the elements thereof to render the variable spacing feed mechanism inoperative.

Figure 12 is a view similar to Fig. 11 showing the status of the elements of the switch lever to render the variable spacing feed mechanism ly in a left hand direction in the usual well-- known manner, and an escapement mechanism, designated generally as 12, whereby advance of the carriage in a left hand direction progresses step-by-step in response to depression of the keys. Apart from the present variable spacing feed mechanism the machine includes, of course, various other mechanisms, but as these do not enter into the present invention, no special effort has been made to illustrate the same and they will not be described.

In general, the present variable spacing feed mechanism is similar to the variable spacing feed mechanism illustrated, described and claimed in my prior patent #1312904. That is to say, a rack bar 13, constituting part of the carriage escapement mechanism, is mounted on the carriage for longitudinal movement relative thereto, a track element 14 extends transversely of the machine at the back thereof and has pivotal connection with the frame of the machine whereby it may be adjusted to extend at different inclinations relative to the path of movement of the carriage, an a bell-crank lever 15 is pivoted to the carriage and has one arm thereof connected to the rack bar 13 and its other arm connected to a track follower. Consequently, since the track follower reacts from the track element through the bell-crank and the rack bar to resist advance of the carriage relative to the rack bar, it follows that for each step of advance of the rack bar the carriage will ad-: vance an equal distance if the track element 'is disposed parallel to the path of movement of the carriage, and will advance a slightly greater distance if the track element is disposed at an outward inclination to the path of advance movement of the carriage, the amount of the gain in movement of the carriage relative to the rack bar depending, of course, upon the inclination of the track element. Thus, in copying previously typed sheets, lines which are shorter than normal may be lengthened by increasing the spacing between characters and groups of characters so that all of the lines will be of the same length.

In certain types of typewriting machines the carriage escapement mechanism, is inclusive of a pawl or pawls cooperating with a carriage carried ratchet bar, and in other types of machines the escapement mechanism includes a rack bar carried by the carriage and having a pinion cooperating therewith. In machines of the latter type the rack bar usually is mounted on levers which are pivoted to the carriage so that the" bar may be raised to disengage it from the pin-- ion thus to permit advancement of the carriage. The machine illustrated in the present instance is of the latter type. Therefore, in order to provide for vertical movement of the rack bar 13' ally as 37, are carried by the block 35 for coopas well as for longitudinal movement thereof relative to the carriage,.the levers 16 'which ordinarily are rigidly connected. together by the rack bar, are, instead, connected together by a bar 17 and the rack bar 13 is mounted in suitable guides 18 on said bar 17 for longitudinal movement relative thereto. Of course, if an escapement mechanism is employed which does not require vertical movement of the carriage carried rack or ratchet bar, then obviously provision for such movement of the bar is unnecessary.

According to the present specific construction, a track element supporting bar 19 is mounted transversely of the typewriting machine at the back thereof on brackets 20 which are secured rigidly to the frame of the machinejand in order that said bar may be longitudinally adjusted and secured in any desired position of such adjustment, the same is slottedfor the reception of the screws or other fasteners 21 by means of which it is secured to the brackets 20. Moreover, to facilitate adjustments of said bar, one of the brackets 20 is provided with an car 22 having threaded therein a screw 22' which engages the adjacent end of the bar.

The bar 19 is toothed or notched along one edge thereof as indicated at 23, and the track element 14 is mounted on said bar through the instrumentality of a block 24 which is slidably adjustable along the bar, the block carrying conventional or any desired means, indicated generally as 25, for cooperation. with the teeth or notches of the bar to hold the block in any desired position of adjustment therealong.

The track element 14 is of L-shape in cross section and at one end is provided with a depending pin 26 which is received in an opening 27 in the block 24, whereby the track element is mounted, not only for longitudinal adjustments with said block, but also for pivotal or swinging movement in a horizontal 'plane so that its inclination with respect to the path of movement of the carriage 11 may be varied.

For varying the inclination of the track ele-. ment 14; means as illustrated and described in my aforesaid prior patent, No. 1,712,904, are employed. That is to say, brackets 28 are secured to the frame of the typewriting machine at the rear thereof and have rotatably mounted therein a shaft 29 to which are aflixed arms 30 which are connected together by a bar 31. This bar 31 thus is mounted for vertical swinging movement and is so swingable in varying, amounts by means of keys 32 which are operatively connected to one of the arms 30 by a rod 33.

As the means illustrated in my aforesaid prior patent, or any other suitable means, may be employed for swinging the bar 31, and as the pres ent improvements are not concerned with the specific nature of such means, greater detailed illustration and description of such means is deemed to be unnecessary.

The bar 31 is toothed or notched along one edge, as indicated at 34', and has mounted thereon for slidable adjustment therealong a block 35, which block carries a suitable formation 36 for cooperation with the track element 14 so that by vertically swinging the bar 31-and, with it, the block 35, the inclination of the track element relative to the path of movement of the carriage 11 may be varied, due, of course, tojthe arcuate movement of the formation 36 resulting from swinging of the bar 31. Means, indicated genereration with the teeth or notches 34 of the bar 31 wherebythe block may be lield'inany desired position of adjustment along said bar, and

in order to assure constant cooperation or en-' gagement of the track element 14 with the formation 36 of said block, a spring 384s provided at the connection of the track element with the block 24 to urge the track element constantly rearwardly against the formation'36.

Referring now particularly'to Figs. 1, 3 and 4 of the drawings, it will be observed that a horizontally disposed plate 39 is secured rigidly to the bell-crank lever 15 having a forwardly extending arm 41 which'is connected to the rack bar 13 by a rod or link 42, and a laterally extending arm 43 which is connected to a bar, 44 by a link 45 whereby the said bar, which is mounted for straight line forward and rearward movement, may so move irrespective of the arcuate move.- ment of the related bell-crank arm.

A rearwardly extending bracket 46 is fastened to the plate 39 and has a downwardly directed, apertured rear end portion receiving the rear end portion of the bar 44, while-a suitable guide 47 afiixed to the under side of the plate 39 accommodates the front end portion of said bar. Thus, said bar 44 is slidably mounted on the plate 39 for straight line forward and rearward movement, and by 'saidbbar is carried a. track follower, preferably in the form of a roller 48, forcooperation with the track element 14. It thus follows that since the advance. movement of the carriage 11 is controlled by the bell-crank lever 15 reacting from the track element 14 through the roller 48 and the connection of the bell-crank lever with the rack bar 13, for each step of advance of the rack bar the carriage will advance a slightly greater amount as permitted by the slidable connection thereof with the rack bar and depending upon the inclination of the track element relative to the path of movement of the carriage.

As hereinbefore indicatedfla special feature of the invention resides in the provision of means whereby the point of contact of the track follower or roller 48 with the track element is held against longitudinal shifting movement relative to the carriage 11 despite pivotal movements of the bellcrank lever 15 which occur, ,due to the inclinathe point of contact of the track element would shift circumferentially of the roller depending upon the inclination of the track element and the desired object would not be completely accomplished. Accordingly, the present improvements also include means whereby the point of contact of the roller 48 with the track element 14 always remains fixed relative to the carriage 11 irrespective of variations in the inclination of the track element, and this means consists primarily in mounting the roller on the bar 44 for swinging movement relative thereto so that the point of contact of the roller with the track element will always coincide or aline with a fixed point on the bar 44. In other words, referring particularly to Figs. 6 to 10 of the drawings, it will be observed that the roller 48 is pivoted to a disk-like member 49 which itself is pivoted to the bar 44 as indicated at 50, and that the diameter to the track element. Consequently, this disof the roller is such that its periphery is alined tive to the carriage is avoided.

In connection with the mounting of the roller 48 on the bar 44 through the instrumentality of the member 49 it is desirable, although not essential, to provide means to assure swinging of the roller in response to variations in the inclination of the track element 14, and to this .end the member 49 is provided with a fin 51 to ride against the track element, and a spring 52 is provided which tends constantly to rotate the member 49 in a direction to maintain said fin engaged with the track element. The end portion of the fin which engages the track element is so disposed relative tothe pivot 50 of the member 49 and the roller pivot that when the said end portion of the fin is in contact with the track element a line drawn through the .pivot 50 and the roller pivot is at right angles position of the roller relative to the track element always is maintained. A pin orabutment 53 is provided on the bar 44 to be engaged by a shoulder or stop on the member 49 to limit swinging movement of the member 49 under the influence of the spring 52.

Referring now to the present switch mechanism for selectivelyrendering the variable spacing feed mechanism operative and inoperative, it will be observed that an arm 54 is pivoted tothe under side of the plate '39 for forward and rearward swinging movement and that said arm is notched as shown to provide a shoulder 55 for cooperation with a lug or pin 56 on the arm 41 of the bell-crank lever 15, so that when said arm. 54 is in a forwardly sw n position, as illustrated in'Fig. 4, the bell-crank lever 15 is held in a position holding the bar 44 and the track, follower retracted and therefore inoperative, and when said arm is in a rearwardly swung position, as illustrated in Fig. 3, free swinging-movement of the bell-crank lever and consequent cooperation of the track follower is permitted.

An apertured ear 57 is carried by the arm 54 and has extending loosely therethrough a rod 58 carrying a pair of spaced abutments 59 and 60. The rod extends in a left hand direction from the arm'54 and is connected to a trigger device at the upper left hand part of the carriage 11,

as illustrated in Fig. 1 of the drawings, and the abutment 59 is positioned at a point on said rod a coil spring 62 surrounds the rod 58 between the ear 5'? and the abutment 60, so that when the rod is moved a predetermined distance in a left hand direction, the spring is compressed against the ear with consequent tendency to swing the arm 54 forwardly to the position in which it holds the bell-crank lever inoperative. In this connection it will be observed that when the bell-crank lever is released by rearward swinging movement of the arm 54, and the arm 41 of said lever subsequently swings to the right, the lug or pin 56 moves across the forward edge of the arm 54 and therefore prevents said arm from returning to a position to hold the bell-crank lever against movement until the bell-crank lever has been returned to its position shown in Fig. 4, which is the position to which the bell-crank lever always is moved bythe cooperation of the roller 48 with the track element 14 when the carriage 11 is moved to a position in which the roller 48 is disposed directly forwardly of the pivotal connection 26 of the track element with the block 24.

Referring now to the aforementioned trigger device of the switch mechanism, which device is illustrated in detail in Figs. 11 to 13 of the drawings, it will be observed that a plate 63 is secured rigidly to the carriage 11 at the upper left hand portion thereof and has rigid therewith near the bottom thereof, a rearwardly extending pin 64 on which is pivoted, intermediate its ends, a substantially vertically disposed lever 65 the lower arm 66 of which is connected to the rod 58. Thus, when said lever 65 is swung in aright hand direction against a stop 67 on 1 the plate 63, a pull is exerted on the rod 58 to compress the spring 62 against the ear 57 to cause the arm 54'to. swing forwardly to latch the bell-crank lever 15 in an inoperative position. On the other hand, when the lever 65 is 1 swung in a lefthand direction, the rod 58 obviously is pushed to a position in which the abutment 59 engages the ear 5'7 and swings the arm 54 rearwardly to a bell-crank releasing position, provided rearward swinging movement of 1 said arm 54 is not prevented.

On the upper arm 68 of the lever 65 is pivoted a latch 69 having a vertical arm "70 which extends above the upper end of the lever arm 68 and a lateral arm 71 which extends in a right 1 hand direction and which is provided with an upwardly projecting nib 72 for cooperation with a pin 73 carried by the plate 53. By means of a spring 74 which is attached at one end to a disk 75 non-rotatably mounted: on the pin 64 1 and at its other end to the latch 69, the latch is constantly urged in a left hand direction with tendency to engage a flange or stop 76 on the lever arm 68 thus to impart swinging movement to the lever 65in a left hand direction. However, when the lever 65 is in its upright, or substantially upright, right hand position, against the stop 67, exerting a pull on the rod 58, said lever is held in this position against the force of the spring '14 by engagement of the latch nib '72 with the right hand side of the pin '73. Consequently, it follows that .if the arm '70 of the latch'is pushed in a right hand direction to disengage the nib 72 from the pin '73 the spring '74 then will act to throw thelever 65 in a left 1 hand direction and to exert a, pushing action on the rod'58. Now, in view of the foregoing, assuming that the variable ,spacing feed mechanism is operative, as illustrated in Fig. 3 of the drawings, that 1 the trigger device is in its left hand swung position as illustrated in Fig. 12, (it being remembered that this is a rear view and that the trigger device must be in its left hand swung position when the variable spacing feed mechanism is operative) and that it is desired to render said feed mechanism inoperative, the procedure consists simply in placing the finger against the left hand side of the lever arm 68 and pressing said lever arm to the right until the nib 72 rides beneath and engages behind the right hand side of the pin 73 as illustrated in Fig. 11 of the drawings. This obviously results in the lever -65 being latched in its right hand position with the rod 58 pulled to a position in which the spring 62 is compressed against the car 57. Consequently, when the carriage 11 is moved to a position in which the roller is opposite the pivot 26 of the track element 14, which means that the bell-crank lever 40 then is in the position illustrated in Fig. 4 of the drawings, the arm 54 is swung forwardly by the, compressed spring 62 and the bell-crank lever is latched against movement by reason of the shoulder 55 of the arm 54 engaging the lug or pin 56. Assuming, on the other hand, that the variable spacing feed mechanism is inoperative, as illustrated in Fig. 4 of the drawings, that the trigger device is in its right hand swung position as illustrated in Fig. 11, and that it is desired to render the variable spacing feed mechanism operative, the procedure consists simply in placing the finger against the upper end of the arm 70 of the latch 69 and pressing said arm in a right hand direction to disengage the latch nib 72 from behing the pin '73, whereupon the spring 74 operates to swing the lever 65 in a left hand direction to cause the abutment 59 to engage the ear 5'? and to swing the arm 54 rearwardly to release the bell-crank lever, provided, as aforesaid, that rearward swinging movement of said arm is not prevented. If it is, then the spring '74 maintains a pushing force on the rod 58 so that the arm 54 is swung to release the bell-crank lever immediately the restraining influence against said arm is removed. In this connection a feature of the invention resides in the provision of means whereby, in the event the trigger device is swung to a position to render the variable spacing feed mechanism operative when the roller 48 is disposed beyond the right hand side of the pivoted or right hand end of the track element 14, the bell-crank lever 15 will not be released until the roller is safely in a position for cooperation with the track element, and this means now will be described.

First, it is pointed out that when the variable spacing feed mechanism is operative, all

lines to be typed begin when the carriage 11 is in a right hand position with the roller 48 directly in front of the pivot 26 of the track element 14, as this represents what may be termed a zero position from which the variable spacing begins. Accordingly, since the track element is adjustable across the typewriting machine by reason of being mounted on the slidably adjustable block 24, which adjustment is for the purpose of variably predetermining where the lines shall begin on a sheet, means must be provided to assure that each time the carriage is returned to a starting position the roller 48 will be disposed directly forwardly of the track element pivot 26 regardlessv of the position of adjustment of the block 24 along the bar 19. This means consists in the present instance of a stop element 77 on the block 24 and a cooperating finger '78 mounted on the under side of the carriage carried plate 39, said stop element and finger being so disposed relative to the track element pivot 26 and to the roller 48, respectively, that when the finger is in abutting relationship to the stop element the roller is disposed directly in front of the pivot 26. In this connection it will be noted that the stop element is slotted and is secured to the block by screws 79 passing through the slots thereof, whereby the stop element may be longitudinally adjusted relative to the block 24 to assure accuracy of alinement of the roller forwardly of thepivot 26. Also, it will be noted that in order tofacilitate accurate adjustments of the stop element, a screw 80 is threaded in a lug 81 on the block 2% and cooperates with the end of the stop element.

When the variable spacing feed mechanism is inoperative it is desirable that the finger 78 shall not interfere with return movement of the carriage 11, so that the carriage may be moved in a right hand direction beyond the point where the roller 48 is disposed directly forwardly of the pivot 26, thereby to permit the use of the usual stop for predetermining the left hand margin of a typed sheet. Accordingly, a feature of the invention resides in the provision of means whereby the finger '78 is moved to an inoperative position relative to the stop 7'7 when the variable spacing feed mechanism is rendered inoperative. In this connection it will be observed that the finger 78 is pivoted for vertical swinging movement on a pin 82 which projects laterally from a lug 83 depending from the plate 39, and that rigid with said finger 78 is an arm 84 which extends in a direction opposite to the arm 78 and carries a laterally extending pin 85 directly underto ride over the pin 85 when said rod 58 is pulled to render the variable spacing feed mechanism inoperative, thereby to depress the arm 84 and elevate the finger 78 to a position where it will pass freely over the stop 77. Thus, whenever the rod 58 is in the position shown in Fig.

4, holding the variable spacing feed mechanism inoperative, the finger 78 is maintained elevated, whereby it will not engage the stop 77 when the carriage is moved to the right. Consequently, the machine then is capable of use in conventional manner and the usual stop may be employed to predetermine the left hand margin of a sheet being typed. On the other hand, when the rod 58 is pushed to release the variable spacing feed mechanism, the cam formation 86 is moved to the front above the pin 85 and the finger '78 is permitted to drop to an operative position.

Reverting now to the means whereby the bellcrank lever 40 is held against release in the event the trigger device is manipulated to render the variable spacing feed mechanism operative when the carriage is in a position with the roller 48 disposed beyond the right hand end of the track element 14, it will be observed that on, a vertical pin 87 depending from the plate 39 is intermediately pivoted a two-arm stantly to swing the lever 88 in a direction to throw the arm 90 rearwardly and the arm 89 to a position behind the free end of the arm 54, so that whenever the arm 54 is in the position shown in Fig. 4 holding the bell-crank lever 15 against movement, the arm 54 itself is held by the arm 89 against swinging rearwardly to a position to release the arm 54, even though the trigger device may be released and in a position exerting a pushing force through the rod 58 and the abutment '59 against the car 57. Now, when thelever 88 is in the position shown in Fig. 4. the projection 91 is disposed to engage one or the other of the inclined surfaces of the cam formation 92, depending upon the direction of movement of the carriage, and in this con-. nection the dispositions of the projection 91 relative to the roller 48, and of the cam 92 relative to the right hand end of the track element 14, are such that when the carriage is moved in either direction, the cam actuates the lever 88 to release the arm 54 only when the roller is safely over the right hand end of the track element 14. Assuming therefore, that the trigger device has been actuated to render the variable spacing feed mechanism operative at a time when the carriage 11 is.in an extreme right hand position with the roller 48 disposed beyond the right hand end of thetrack element 14, it is apparent that the trigger device spring 74exerts a force on the lever 65 tending to swing said lever in a left hand direction, but that the rod 58 is held against being pushed by the lever 65 to swing the arm 54 rearwardly to release the bell-crank 15, due to the arm 89 of the lever 88 being held by the spring 93 in a latching position behind the arm 54. Therefore, even though the trigger device is actuated to render the variable spacing feed mechanism operative when the roller 48 is beyond the right hand end of the track element 14', the feed mechanism does not immediately become operative. On the contrary, it becomes operative only when the carriage is moved so far to the left that the roller 48 is safely over the right hand end of the track element, at which time the cam 92 functions to swing the lever 88 torelease the arm 54, whereupon the trigger spring 74 may then function to push the rod 58 to swing the arm 54 to release the bell-crank lever, thus to place the roller 48 into cooperative relationship to the track element. And the same operation occurs if the trigger device'is actuated to render the variable spacing feed mechanism operative when the roller is disposed between the ends of the track element. On .the other hand, if the trigger device is actuated to render the variable spacing feed mechanism inoperative at any time other than when the roller 48 is disposed directly forwardly of the track element pivot 26, the feed mechanism does not immediately become inoperative but is rendered automatically inoperative when, by return movement of the carriage 11, the roller 48 by cooperation with the track element swings the bell-crank lever 15 until the arm 54 can move to a holding position relawear is latched in the position of Fig. 11 a pull is exerted on the-rod 58 and the spring 62 is compressed against the ear 57, and at the same time the cam 86 operates to lift the finger 78 so that it may ride over the stop 77. The carriage may, therefore, be returned to its extreme right hand position, or as far to the right as may be permitted by the usual stop, but when the roller 48 reaches a position directly forwardly of the track pivot 26 the bell-crank lever 15 then is in a position to permit the arm 54 to move to the holding position shown in Fig. 4, whereupon the spring 62 acts to move said arm to said position, and the spring 93 acts to swing the arm 89 of the lever 88 to the position of Fig. 4 to hold the arm 54 against swinging to release the bell crank until the roller again is brought to a posi tion directly forwardly of the track pivot 26. Since, in general, the mode of operation of the present mechanism is the same as described in my aforesaid prior Patent No. 1,712,904, further detailed description is deemed to be unnecessary, other than to point out that the bell-crank lever 15 preferably is formed'in two adjustable sections whereby the relative disposition of the

arms

41, 43 thereof may be varied to suit particular installations, and that a stop 94 preferably is provided on the trigger lever 65 to limit swinging movement of the latch lever 69 in an unlatching direction.

From the foregoing description considered in connection with the accompanying drawings, it is believed that the construction, operation and advantages of the invention will be clearly understood. It is desired to point out, however, that while only a single specific embodiment of the improvements constituting the invention has been illustrated and described, the said improvements 'are readily. capable of embodiment in various other mechanical structures within the spirit and the scope of the invention as defined in the appended claims.

I claim:

1. In a typewriting machine, a carriage, an escapement mechanism therefor including a bar which is advanced step-by-step in response to actuation of the typewriter keys and with respect to which the carriage is longitudinally movable, and a variable spacing feed mechanism for the carriage comprising a track element to be disposed at an inclination to the path of travel of the carriage, a track follower, a bellcranl: lever pivoted to the carriage and having one arm connected to the aforesaid bar and its other arm connected to said track follower, and means whereby any shifting of the point of contact of the track follower with the track longitudinally of the carriage is at all times prevented.

2. In a, typewriting machine, a carriage, a track element to be disposed at an inclination to the path of travel of .the carriage,- a track follower carried by the carriage, means reacting from the track element through said track follower to produce variable feed movement of the carriage in accordance with the inclination of the track element, and means whereby any shifting of the point of contact of the track follower with the track longitudinally with respect to the carriage is at all times prevented.

3. In a typewriting machine, a carriage, an escapement mechanism therefor including a mean/e bar which is advanced step-by-step in response to actuation of thetypewriter keys and with respect to which the carriage is longitudinally movable, and a :variable spacing feed mechanism for the carriage comprising a track element to be disposed at an inclination to the path of travel of the carriage, a track follower, a member carrying said track follower and mounted on the carriage for straight line forward and rearward movement relative to the carriage, the track follower being swingably connected to said member, and means connecting said member to said bar and operable in response to the cooperation of the track follower with the track element to produce variable feed movement of the carriage in accordance with the inclination of the track element.

4. In a typewriting machine, a carriage, an escapement mechanism therefor including a bar which isv advanced step-by-step in response to actuation of the typewriter keys and with respect to which the carriage is longitudinally movable, and a variable spacing feed mechanism for the carriage comprising a track element to be disposed at an inclination to the path of travel of the carriage, a track follower, -a member carrying said track follower and mounted on the carriage for straight line forward and rearward movement, and a bell-crank pivoted to the carriage and having one arm connected to said member and its other arm connected to the aforesaid bar.

5. In a typewriting machine, a carriage, a track element to be disposed at an inclination to the path of travel of the carriage, a bar mounted on the carriage for straight line forward and rearward movement, a track follower swingingly mounted on said bar whereby the point of contact between the trackfollower and the track element remains at the same point, longitudinally of the carriage irrespective of variations in the inclination ofv the track element, and meansconnected to said bar and operable in response to longitudinal movement thereof as controlled by the track element to produce variable feed movement of the carriage in accordance with the inclination of the track element.

6. In a typewriting machine, a carriage, an escapement mechanism therefor including a bar which is advanced step-by-step in response to actuation of the typewriter keys and with respect to which the carriage is longitudinally movable, and a variable spacing feed mechanism for the carriage comprising a track element to be disposed at different inclinations to the path of movement of the carriage, a member mounted on the carriage for straight line movement forwardly and rearwardly thereof, a bell-crank lever pivoted to the carriage and having one arm connected to said bar and the other arm connected to said member, and a track follower in the form of a roller mounted on said member for swinging movement with respect thereto, whereby the point of contact between the roller and the track element always remains in a straight line forwardly and rearwardly of the carriage irrespective of variations in the inclination of the'track element.

'7. In a typewriting machine, a carriage, an escapement mechanism therefor including a bar which is advanced step-by-step in response to actuation of the typewriter keys and with respect to which the carriage is longitudinally movable, and a variable spacing feed mechanism for the carriage comprising a track element to be disposed at different inclinations to the path of movement of the carriage, a member, mounted on the carriage for straight line movement forwardly and rearwardly thereof, a bellcrank lever pivoted to the carriage and having one arm connected to said bar and the other arm connected to said member, a track follower in the form of a roller mounted on said member for swinging movement with respect thereto, and means for positively swinging the roller in response to changes in the inclination of the track element, whereby the point of contact between the roller and the track element always remains in a straight line forwardly and rearwardly of the carriage irrespective of variations in the inclination of the track element.

8. In a typewriting machine, a carriage, an escapement mechanism including a bar which is advanced step-by-step in response to actuation of the typewriter keys andwith respect to which the carriage is longitudinally movable, a variable spacing feed mechanism for the carriage comprising a track element to be disposed at different inclinations to the path of movement of the carriage, a track follower, a bellcrank lever pivoted to the carriage and having one arm thereof connected to said bar and the other arm thereof connected with said track follower, a switch controlling the operation of said variable spacing feed mechanism, means whereby the switch may be actuated to reverse the status of said mechanism when the carriage is in any position, and means whereby the status of the feed mechanism is reversed in response to actuation of the switch only when the carriage is in a single definite position.

9. In a typewriting machine, a carriage, a variable spacing feed mechanism therefor, a switch controlling the operation of said feed mechanism, means whereby the switch may be actuated to reverse the status of the feed mechanism'when the carriage is in any position, and means whereby the status of the feed mechanism is reversed in response to actuation of the switch only when the carriage is in a single definite position.

10. In a typewriting machine, a carriage, a variable spacing feed mechanism therefor including a track element and a carriage carried follower, a switch controlling the operation of said feed mechanism, means whereby the switch may be actuated to reverse the status of the feed mechanism when the carriage is in any position, and means whereby the status of the feed mechanism is reversed in response to actuation of the switch only when the track followeris disposed in cooperative relationship'with the track element at a point on the latter corresponding to a line beginning position of the carriage.

11. In a typewriting machine, a carriage, an escapement mechanism including a bar which is advanced step-by-step in response to actuation of the typewriter keys and with respect to which the carriage is longitudinally movable, a variable spacing feed mechanism for the carriage comprising a track element to be disposed at different inclinations to the path of movement of the carriage, a track follower, a bell-crank lever pivoted to the carriage and having one arm thereof connected to said bar and the other arm thereof connected with said track follower, an arm pivoted to the carriage for swinging movement between a position to hold the bell-crank lever against movement with the track follower fully retracted and a position to release the bellcrank, a rod movable with respect to said arm and having apair of abutments one for cooperation with the arm to swing the same to a bellcrank releasing position when the rod is moved in one direction, a spring between the arm and the other abutment to be compressed against the arm when the rod is moved in the other direction with consequent tendency to swing the arm to, a bell-crank holding position, a trigger lever connected to said rod, means for latching the trigger lever in a position in which said spring is held compressed, and a spring effective when said trigger lever is unlatched to tend to throw the same in a direction to actuate said rod to swing said arm to. a position to move said arm' to a released position relative to the bell-crank.

12. Ina typewriting machine, a carriage, a variable spacing feed mechanism therefor, and means to render said feed mechanism operative and inoperative, said means comprising a trigger lever movable between restrained and released positions in any position of the carriage, spring means rendered effective when the trigger lever is in a restrained position to tend to render the feed mechanism inoperative, spring means rendered effective when the trigger'lever is released to tend to render the feed mechanism operative, and means operable in response to movement of the carriage to permit one or the other of said springs to act to render the feed mechanism inoperative or operative, depending upon the position of the trigger lever.

13. In a typewriting machine, a carriage, a

variable spacing feed mechanism therefor, and

means to render said feed mechanism operative and inoperative, said means comprising a trigger lever movable between restrained and released positions in any position of the carirage, spring means rendered effective when the trigger lever is in a restrained position to tend to render the feed mechanism inoperative, spring means rendered effective when the trigger lever is released to tend to render thefeed mechanism operative, means operable to prevent the status of the feed mechanism being reversed except when the carriage is in a single definite position, and means operable in response to movement of the carriage to said position to permit one or the other of said springs to act to render the feed mechanism inoperative or operative, depending upon the position of the trigger lever.

14. In a typewriting machine, a carriage, a

variable spacing feed mechanism therefor inclusive of a track element and a cooperating carriage carried track follower, and means to render said feed mechanism operative and inopneaaive erative said means comprising a trigger lever movable between restrained and released positions in any position of the carriage, means rendered eifective when the trigger lever is in a restrained position to tend to render the feed mechanism inoperative, means renderedeffective when the trigger lever is released to tend to render the feed mechanism operative, means operable to prevent the status of the feed mechanism being reversed except when the carriage is in a single definite position with the track follower operatively disposed with respect to the track, and means operable in response to movement of the carriage to said position to permit one or the other of said trigger controlled ing carriage carried track follower, means to render the feed mechanism operative and inoperative comprising a trigger lever movable between restrained and released positions in any position of the carriage, yieldable means rendered efiective when the trigger lever is in a restrained position to tend to render the feed mechanism inoperative, yieldable means rendered efiective when the trigger lever is in a released position to tend to render the feed mechanism operative, stop means rendered efiective when the trigger lever is in a released position to limit return movement of the carriage to a position in which the track follower is in cooperative relationship to the pivoted end of the track element, means whereby movement of the trigger lever to its restrained position renders said stop means inoperative so that the carriage may partake of its complete normal return movement, means operable to prevent the status of the feed mechanism being reversed except when the carriage is in a position with the track follower in cooperative relationship to the pivoted end of the track element, and means operable in response to movement of the carriage in either direction to said position to permit one or the other of said yieldable means to act to render the feed mechanism inoperative or operative, depending upon the position of the trig- Y ger lever.

ROCHFQRT WYBRANTS RGBINSON.