US1515438A - hokanson - Google Patents

Description

Nov. 11 1924. 1,515,438

0. HOKANSON RIBBON MECHANISM FOR TYPEWRITERS Filed Sent. l3 1920 a Shuts-Shut 1 izz/57274;;

NOV.

O. A. HOKANSON RIBBON MECHANISM FOR TYPEWRITERS Filed Sent. 13. 1920' 3 Shuts-Sheet. 2

I'll! ILI IaLI l l I l l I I II llllllllll NOV. 11 1924.

. O. A. HOKANSON RIBBON MECHANISM FOR TYPEWRITERS Filed Sept. 13. '1920 3 Shuts-Shoot 3 Patented Nov. 11, 1924.

UNITED STATES PATENT OFFICE.

OTTO A. HOKANSON, O1" WOODSTOCK, ILLINOIS, ASSIGNOR TO WOODSTOCK TYPE- WRITER COMPANY, OF WOODSTOCK, ILLINOIS, A CORPORATION OF ILLINOIS.

RIBBON MECHANISM FOR TYPEWRITERS.

Application filed September 13, 1920. Serial No. 410,044.

To all whom it may concern:

Be it known that I, 'r'ro A. HoKANsoN, a citizen of the United States, residing at \Noodstock in the county of McHenry and State of Illinois. have invented certain new and useful Improvements in Ribbon Mechanism for Typewriters, of which the following is a specification.

This invention relates to typewriting machines and more specifically to mechanism for holding and controlling the ribbons for typewriters, and has for its object the provision of machines of the class named which shall be of improved construction and operation.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawings and described in the following specification, and it is more particularly pointed out in the appended claims.

In the drawings- Fig. 1 is a vertical section of a portion oi" a typewriter with parts in elevation illustrating one embodiment of the invention;

Fig. 2 is a horizontal section showing the operating mechanism for a ribbon spool at one side of the typewriter;

Fig. 3 illustrates the corresponding mechanism at the opposite side of the typewriter from that shown in Fig. 2;

Fig. 4 is a vertical section through the ribbon spool and associated parts; and

Fig. 5 is a fragmentary view with parts in section showing portions of the ribbonfeeding mechanism.

Although the present invention is applicable to various forms of typewriters, it is illustrated in connection with a typewriter having a frame in which the platen carriage is mounted for movement into and out of operative position to permit the typewriter to be folded into compact form.

A base frame is provided with a pair of arms 11 pivotally mounted at 12 on opposite sides of the frame 10. A platen carriage frame 13 is secured to the ends of the arms 11 and is provided with a platen carriage 14 arranged to travel thereon. A platen 15 is journaled on the carriage 14. to move therewith. Each of the arms 11 has a flange 16 formed thereon to which a bracket 17 is secured, the bracket 17 being provided with a lower arm 18 and an upper arm 19, as shown best in Figs. 3 and 4. A ribbon spool shaft or spindle 20 is journaled in the arms 18 and 19 and is provided with a ratchet wheel :21 and a collar 22 at its lower end, both rigidly secured to the shaft 20. A collar 23 is "fastened to the shaft 20 above the bracket arm 19 by means of a set screw or other holding device, and a pin 2% projects upwardly from the upper face of the collar 23 in position to engage an opening 25 in a detachable ribbon spool core 26. The core 26 is preferably made of wood and fits over the end of the spindle 20 above the collar 23. A knurled head 27 is provided with a screw 28 having threaded engagement with an opening 29 formed in the upper end of the spindle 20. A cover disc 30 is mounted on the screw 28 adiacent the lower ,face of the head 27 and although tree to rotate on the screw as a pivot it is held from displacement by a shoulder provided by the edge of a peripheral groove in the screw in which the disc 30 is held. A number of points 31 are formed on the lower face of the disc 30 so that when a core 26 with the ribbon wound thereon has been slid over the upper end of the spindle 2O the head 27 may be threaded into the opening 29 so as to press the points 31 into the end oi the core 26 while the disc 30 and core 26 remain stationary relative to one another. A housing 32 is secured to the upper bracket arm 19 to enclose the ribbon and the disc 30 forms a cover plate above the housing when the ribbon is in place. Rotation of the ribbon spool is produced by the ratchet wheel 21 which is operated by mechanism to be described.

As will be seen from Fig. l the bracket 17 is inclined at an oblique angle to the arm 11 so that the spindle 20 is inclined to the vertical when the arms 11 are in operating position. This makes it possible to mount the ribbon spools and their housings somewhat below the horizontal level oi the axis of the platen 1:3 and yet support the ribbon so that its surface will be tan gent to the surface of the platen.

A detent pawl 33 is provided with a pair of ears 34 and 35 pivoted on a stud 36 extending downwardly from the upper flange of the arm 11. The ears 34 and 35 with the end of the pawl 33 constitute a yoke which forms a guide for an operating pawl 37 which extends between the ears 3% and 35 and between the pawl 33 and its pivot 36. The ends of the pawls 33 and 37 are bent inwardly and beveled, as shown in Fig.2, so as to engage the teeth on the ratchet wheel 21. The rear end of the pawl 37 is pivotally mounted at on a lever A. lug 40 is formed on the ear 3% of the pawl 33 and a similar lug 41 is formed rigidly with the pawl 37 near the pivot 33. The lugs 40 and 41 are connected by a spring 42 which tends normally to throw both pawls 33 and 37 into contact with the ratchet wheel 21., The lever 39 is pivoted 43 on a bar M which extends across the chine from one side to the other thereof. The movement of the lever 39 about its pivot 43 is limited by a pin 4 5 which extends into an opening 46 in the lever 39. The end 47 of the lever 39 is arranged adjacent the upper end of a universal member 4'8. The universal member 13 extends upwardly from the base frame 1) and is vibrated at each operation of the typewriter keys in any wellknown manner. When the parts are in the position shown in Fig. 2 vibration of the universal member 43 toward the front of the machine brings the member into enegagment with the end 47 of the lever 39 and moves the lever about its pivot 3 so as to retract the operating pawl 37. This will shift the pawl. 37 backwardly an amount sufficient to engage a notch on the ratchet wheel 21, and when the universal member 48 is released the spring 42 will return thepawl 37 to its forward position, thus advancing the ratchet wheel 21 a space corresponding to, one tooth on the ratchet wheel. This feeding operation of the typewriter ribbon will take place at each operation of a typewriter key until the ribbon has been entirely unwound from the spool :it the opposite side of the typewriter. The position of the mechanism for controllii the spool from which the ribbon is being ruiwound is shown in 3. The bar being shifted to the left retains the pivotal support 38 for the inactive pawl 37 in position to swing the forward end of the pawl 37, about the pivot stud 35 so that the end of the pawl is disengaged from the "atchet wheel 21 and caused to bear against the inner face of the pawl 33 so that both pawls are held out of mesh with the teeth of the ratchet wheel. This leaves the ratchet wheel and ribbon spool at the right-hand side of the typewriter, as viewed in Figs. 2 and 3, free to rotate as the ribbon is withdrawn therefrom.

For the purpose of reversing the direction of operation of the ribbon spools when the ribbon has been completely unwound from one of the spools a yoke 49 is pivotally mounted on a rod 50 carried by the ends of the bracket arms 18 and 19. The yoke 49 is provided with an upper arm 51 as shown in Figs. 1 and 3, having an upwardly extending finger 52 provided with a slot 53 through which the ribbon passes as it is unwound from the core 26. The ribbon is shown in broken lines in Fig. 3, and adjacent its end is provided with a stop or thickened portion 54 which is of greater thickness than the width of the slot When the stop engages the slot 53 the arm will be swung about its pivotal axis 50 which will cause the lower arm 55 of the yoke 49 to swing in the same direction as the upper arm 51. A coil spring 56 is secured to the arms 19 and 51 and normally draws the bracket arms 51 and 5." toward the ribbon spool. During the time that the ribbon is being unwound from the right-- hand spool the arm 55 engages a lug 57 on a lever 58 pivoted at 59 on one arm 60 of a bell crank pivotally mounted at 615 on a bracket 62 secured to the platen carriage 'i'rauim as shown in Fig. A spring 63 ly holds the lug 57 against the arm I so that the arm forms a stop to hold the lever 58 from rotation about its pivot 59. W hen the arm 55 is movedto the left, as viewed in Fig. 3, by the ribbon at the manner previously describech the spring 63 will draw the rear end of the lever to the right. as viewed in that figure, bringing it into the path of movement of the universal member 64 corresponding'to the universal member 428 at the opposite side of the typewriter. As soon as this occurs the next operation of the typewriter will cause the universal member 64ltoengage the end of the lever 58 and force the lever forwardly carrying with itthe arm 60 of the bell. crank pivoted at 61. This bell crank is provided with a rearwardly extending arm 65 having a slot 66 formed in the end tl reof .in position to engage a piir 67 carried by the bar 44. One of the bell crank arms 6.3. as shown in Fig. 9.. is provided at its end with a roller 68 for engaging notches 69 and 70 in a detent. The detent 71 is pivoted at 72 on the platen carriage frame 13 and is provided with a spring 73 for holding it in contact with the roller 68. dhen the arm 65 is moved about its pivot by the lever 58 and universal member 64, tile roller 68 will be shifted from the notch 69' to the notch 70, and the bar 4 L will be correspondingly shifted to the right from the position shown in the drawings. This movement of the bar 44 will permit the pawls 33 and 37 in Fig. 3 to come into engagement with their ratchet wheel.

The entire reversing operation takes place at a single stroke of a typewriter key so that there is no period during which the rib hon remains stationary a suiiicient length of time to permit repeated blows ot ti 2 type at one spot. The same movement of the bar Thit will bring the end 47 ot the lever 39 in Fig. 3 into the path of the universal member 64 so that further ope ation of the type writer will rotate the spool in Fig. 3 to rewind the ribbon thereon and to withdraw it trom the spool at the opposite end of the typewriter. When the ribbon has been entirely withdrawn from the opposite spool the ratchet mechanism will again be reversed and thus the ribbon-feeding mechanism will be automatically reversed as often as the ribbon is shifted from one spool to the other.

It will be seen that the ribbon spool holdcrs are mounted on the supporting arms for the platen carriage frame so that the ribbon holders are always in proper position relati ve to the platen whether the frame is tolded or in its operating position. The mechanism for feeding the ribbon is also carried by the platen carriage frame and the arms by which the frame is supported so that its operative relation is not disturbed by the movement 01"? the platen carriage in folding. The universal members 48 and 64 are locatesil so that they are automatically brought into proper position relative to the ribbon "teeding mechanism when the platen carriage Frame is moved into its operating position.

I claim i. In combination, a ribbon spool, means for rotating said spool, mechanism for reversing said rotating means, a movable member for actuating said reversing mechanism, a spring-controlled member for effecting operative connection between said movable member and said reversing mechanism, and a spring-controlled device for retaining said spring-controlled member out of operative position, said device being movable by the ribbon on said spool for per mitting said spring-controlled member to effect cooperative connection between said movable member and said reversing mechanism.

2. Ribbon mechanism tor typewriters comprising a rotary spindle, a ribbon core movable into and out of position on said spindle, means connecting said core and spindle to cause them to rotate in unison with one another, a threaded. member for engaging said spindle to hold said core in place thereon, and a cover plate pivotally carried by said threaded member and having projections thereon arranged to engage said core when said threaded member is connected with said spindle.

3. Ribbon mechanism for typewriters comprising a pair of ribbon spools, a ratchet wheel ior each of said spools, dogs foroperating said ratchet wheels, levers for actuating said dogs, a movable bar on which said levers are pivoted, movable devices for operating said levers when the typewriter is operated, and means controlled by the ribbon on said spools and actuated by one or the other of said movable devices for shifting said bar to reverse the operation of said ribbon mechanism by shifting one of said levers into, and the other out or cooperative relation with its respective movable device.

Ribbon reversing mechanism comprising a sliding bar, a bell crank lever havin g one end thereof connected with said sliding bar, an actuator, a contact device pivot ally connected with said bell crank lever and movable thereon into and out of the path of said actuator, a ribbon spool, operating mechanism for said ribbon spool carried by said bar and movable therewith into and out of operative relation with said actuator, and ribbon control mechanism for moving said contact device on its pivot to cause said contact device to intercept the movement of said actuator and operate said bell crank lever to shift said bar.

Ribbon reversing mechanism comprising a longitudinally movable bar, an actuator, a lever for shifting said bar, acontact device carried by said lever, and means controlled by the ribbon for positioning said contact device in the path of said actuator to cause said actuator to operate said lever and shift said bar, the movement of said lever bringing said contact device beyond the path of movement of said actuator.

G. Ribbon reversing mechanism compris ing a longitudinally movable bar, a ribbon spool, ratchet mechanism for rotating said spool, a lever pivoted on said bar for operating said ratchet mechanism, an actuator for operating said lever, a bell crank lever for shifting said bar, a contact device carried by said lever and movable thereon into and out of the path of said actuator, and ribbon controlled mechanism for permitting said contact device to move into the path of said actuator when the ribbon is unwound from said spool so that said bell crank lever will be operated by said actuator to shift said bar and simultaneously disconnect said ratchet mechanism from said spool and move the operating lever for said ratchet mechanism out of cooperative relation with said actuator.

7. A typewriter comprising a foldable platen carriage frame having pivoted arms at opposite sides of the typewriter, a longitudinally movable bar slidably mounted on said pivoted arms a ribbon spool rotatably mounted on each of said arms, pawls mounted on each arm for rotating the ribbon spool carried thereby, levers mounted on said bar for operating said pawls, bell crank levers having pivots fixed to said platen carriage frame; actuators for each spool supported in- 10 dependently of said platen carriage frame,

contact members o-n each of said bell crank levers, and ribbon controlled means for moving said contact members into the path of said actuators to shift said bar and effect a reversal of said ribbon mechanism.

In testimony whereof I have signed my name to thisspecificati'on on this 7th da of August, A. D. 1920.

oTTo A.- i-ioiktaitsos'.

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