US3825102A

US3825102A - Type head tilt and rotating mechanism

Info

Publication number: US3825102A
Application number: US00308622A
Authority: US
Inventors: H Decker
Original assignee: Triumph Werke Nuernberg AG
Current assignee: TA Triumph Adler AG
Priority date: 1969-12-18
Filing date: 1972-11-21
Publication date: 1974-07-23
Anticipated expiration: 1991-07-23

Abstract

A tilt bridge for a type carrier carries unitarily rotatable thereon a type carrier and a gear, and such gear is in constant engagement with another gear at an axis location whereabout the tilt bridge is required to tilt. The gear on the tilt bridge has freedom for tilting movement about said axis location in respect to the other gear and is in constant mesh therewith for receiving therefrom rotary type-selective movements for the type carrier. The tilt and rotate axes are mounted on a swingable support whereby the carrier may be swung to print.

Description

United States Patent 1191 Decker July 23, 1974 [5 TYPE HEAD TILT AND ROTATING 3,674,126 7/1972 Decker et al. 197/55 MECHANISM 3,703,230 11/1972 Glave 197/52 [75] Inventor: Herbert Decker, Lauf, Germany OTHER PUBLICATIONS 73 A 1 T h w k N b H. E. Merritt, Gears, Sir Isaac Ritman & Sons Ltd., Sslgnee N l l r l ergfefma h y erg (3rd ed.), 1954, pp. 8-9 and 372-375.

[22] Filed: 1972 Primary Examiner-Robert E. Pulfrey 21 APPL 30 22 Assistant Examiner-R. T. Rader Related US. Application Data [57] I ABSTRACT 63 1 58:52:25? of Ser No 1970 A tilt brldge for a type earner carries unitarlly rotatable thereon a type carrier and a gear, and such gear 52] us. c1. 197/55, 197/18 is in constant engagement with another gear at an axis 51 1111. c1 B41] 1/32 locatiohwhereahout the tih bridge is required to 58 Field of Search 197/16, 52, 19, 55, 18; The gear on the tih bridge has freedom for hing 178/34 movement about said axis location in respect to the other gear and is in constant mesh therewith for re- [56] References Cited ceiving therefrom rotary type-selective movements for UNITED STATES PATENTS the type carrier. The tilt and rotate axes are mounted 2 895 584 7/ Son at a 197/52 on a swingable support whereby the carrier may be 219051302 9/1959 l-lickerson swung to punt 3,286,806 11/1966 Schoenfelder 197/16 7 Claims, 3 Drawing Figures PAlimmJmzamu V 5, 35,102

I sum 1 or 2 INVENTOR HERBERT DECK-ER BY M ATTORNEY PAIEN EDJM V 3'.825L102 sum 2 [IF 2 INVENTOR HERBERT DECKER I BYM9 -%b%,

ATTOR NEY , 1. 1 TYPE HEAD TILTAND ROTATING MECHANISM This is a continuation of copending US. application Ser. No. 76,733, filed Sept. 30, 1970, now abandoned.

BACKGROUND OF THE INVENTION In connection with type carriers, in typewriters and similar machines which bear a plurality of type characters in vertical columns and horizontal rows, this invention concerns a provision for selectively positioning such type carrier for effecting type selections.

The positioning of such carriers for any givencharacter selection requires a turning and tilting motion of the type carrier. In order to provide for both such motions, a motion transmitting joint becomes necessary which connects the type carrier and the motion axis in a hingedly jointed manner for smooth motion transmittal. The type carrier can be generally sphere-shaped like with a joint in its center thereof, or it can be barrel shaped. In the latter case a joint is required which affordsa center of a radius curvature in accord with which said barrel 'is shaped. For type carriers which are strictly of cylindrical form and have several rows of characters located in different horizontal rows merely axial motion of the type carrier is required.

A. U.S. Pat. No. 2,895,584 issued July 1, 1959 to .I. E. Hickerson et al. (German Pat. No. 1,063,612), shows that it is well known to position a sphere shaped type carrier by use of two crown gears which have intermediate thereof another crown gear, the axis of such latter crown gear being coincident with the tilting axis of the carrier in order to achieve constant control over the type carrier by said gears. Because the sphere shaped type carrier is small, its hollow interior in which the joints for the gears have to be accommodated are of necessity very small, so that very fine manufacturing tolerances are necessary which raise the cost of manufacture. Furthermore, there is greatly accumulating play in the motion train between the rotating axis and the type carrier, and such play includes the working clearance between thethree crown gears and the pivots therefor. Consequently, in order to hold the total play within acceptable limits, very special and expensive accuracy in all the pertinent parts is required.

In another known execution shown in said I-Iickerson .et al. patent (DPS 1,063,612) of a positioning mechanism for a sphere shaped type carrier a double cross or "universal joint is used to connect the rotating axis and the rotating type carrier. Although this cross joint was simplified as compared to the usual cross joints, it has similar disadvantages as described above with the crown gears arrangement which take the function of a joint. Here too play enters into it twice at the two grooves of the joint members and at the pins of the ro-.

tating axis and on the rotating member onto which the type carrier is mounted- One such connecting member which .is located within the sphere shaped type carrier allows only relatively small links to transmit the forces from the rotating axis to the type carrier. The links are in addition shortened when the carrier is moved into its furtherest positions. A further disadvantage is that because of the amount of rotation which is necessary a certain distance of the joints from the center is required, taking up so 'much space of the space available inside the type carrierthat there is very little'space left to mount the rotating member which carries the type 2 carrier in the axialdirection. Therefore themounting was put on the outside of the joint causing the mounting to have a large diameter which increases the friction.

' Another joint connection became known for a barrel shaped type carrier, see US. Pat. No. 3,286,806 issued to H. Schoenfelder on Nov. 22,- 1966 (French Pat. No. 1,411,426), which consists of a sleeve on the rotating axis and a pin in the rotating member which carries the type carrier. Although with such a joint, it is possible to turn the type carrier and at the same time to tilt it to select a row, a varying motion results from such structure, as is well known. This means that specific different angular rotations of the driver shaft produce at the type carrier angular motions which are differing therefrom. This condition for positioning the type carrier is unacceptable inasmuchas for detenting purposes these differing angular motions have to be corrected before printing. For machines with a constantly rotating type carrier it would require supplemental timing corrections. From this it follows that with type carriers which are turned and tilted to selectively position a particular character, a homokinetic joint is required.

SUMMARY or THE INVENTION Underlying the invention is an object to provide for a rotatable and tiltable type carrier, a joint which will not produce discrepancies of angular motion transmittal between a prime rotating shaft for-such carrier and the carrier in any rotating or tilting range of the type carrier. Furthermore, the requirement is that the connecting joint is within the type carrier and is of simple structure and such as to hold loose play in the drive to the type carrier to a minimum. 7

These objects of the invention are attained in that a connecting joint or provision consists of two gears, which locally mesh and of which one gear is swingable about the location where they locally mesh. The connecting joint is within the barrel-shaped type carrier, and comprises two gears which locally are always in full meshing association where the tilt axis for the type carrier is situated.

DESCRIPTION OF DRAWINGS DESCRIPTION OF PREFERRED EMBODIMENT On a guide rail 1 which is carried between sidewalls of the machine frame, not shown, there is a guided swingably a type carrier support 2. A lower transverse web 3 and an upper transverse web 4, both being a part of the support 2, have respectively holes 5 and 6 which give rotating support to a shaft 7. The lower end of the shaft 7 carries a guide disk or drum 8 whereby it is rotatable. Above the web 4 the shaft 7 carries a crown gear which by a shoulder 9 thereof rests on said web 4. Furthermore, the type carrier support 2 has integral, laterally spaced upwardly extending bearing arms 11 and 12, having each a hole 13 at the upper end thereof whereinto axle studs l4carried on a tilt member or bridge 15 extend thereby to mount such tilt bridge 15 tiltably on the support 2 on a tilt axis which is defined by said holes 13 and the studs 14. A gear 16 in the form of a crown gear is carried fast on an axle 18 by a nut 17. The axle 18 is rotatively supported in a bearing 20' on the tilt bridge 15 with a shoulder 19 rests on the axle 18 resting on the bearing 20. The tilt bridge 15 includes a lever arm 21 depending therefrom and having a hole 22. The upward extending end 23 of the axle 18 is threaded and serves to fasten a barrel-shaped type carrier 24 upon the axle 18 between shoulder 19 and a shoulder of a serrated nut 25 when the nut 25 is applied thereon. The type carrier 24 has type characters 26 arranged thereon in well known manner, in vertical columns and horizontal rows and so that the type characters 26 can be brought selectively into printing position at the platen 27. I

In order to bring a given type character 26 on the type carrier 24. into a position for printing against the platen 27 at a printing point, it is required to impart a rotating motion and tilting'motion tothe type carrier 24, and further to swing the type carrier 24 by the support 2 toward the platen 27 about the guide rail 1. The rotating motion is transmitted to the type carrier 24 by a drawband, not shown, which acts turnably on the drum 8 to turn the shaft 7 and the crown gear 10 thereon. The crown gear 16 which is mounted on the tilt bridge 15 is in constant engagement with the lower crown gear 10 at a location where the pitch circles of the

crown gears

10 and 16 locally meet and at which location furthermorethe tilt axis defined by the holes 13 and the studs 14 is tangent with the pitch circles of

crown gears

10 and 16. Because of this geometric arrangement it is possible to rotate the type carrier 24 selectively while at the same time a tilt motion is imparted to the tilt bridge'15 via the arm 21, by a drive, not shown. To effect an imprint, the support 2 for the type carrier 24 is mounted on the guide rail 1 for swinging movement against the platen 27, the support 2 having normally a position wherein the type carrier 24 stands swung away from the platen 27. Drives for effecting swinging movements of the type carrier 24 are known to exist in different forms and it is not thought necessary to give an explanation thereof.

The device of the invention facilitates the positioning of a type carrier 24 of generally spheric or barrel-- shaped, rotatable form, so that regardless of the tilt position which may be given to the tilt bridge 15, the type carrier 24 will always receive from the shaft 7 the required rotative positioning movement via the

gears

10, 16. For the transmittal of the homokinetic motion there are required only two parts namely the two

gears

10, 16 which preferably may be generally of the crown gear species shown. Therefore, there is no chance for accumulative play, such as is prevalent when universal joint mechanisms are used. A further advantage of the invention resides in the fact that the two

gears

10 and 16 of large diameter can be accommodated within the type carrier 24 yet require very little space in the axial direction, as can be observed especially in FIG. 2. It is for this reason that the mounting means of the rotating shaft 7, as well as the type carrier 24, can be of such efficiently.

. 4 structure thatthe parts will operate not only functionally with precision but are also produceable simply and The connecting joint of the invention, compared to joints involving apin and a slidable fit with a bushing,

has alsospecial advantages afforded by the fact that there is a virtual absence of friction. Thus, wear is reduced so that better accuracy of operation prevails. Furthermore, the forces for transmittal of rotating motion are active far from the rotation axes of the

shafts

7 and 18 and the contact pressure is thus most favorable and uniformly active in any of the various tilt positions of the type'carrier 24.

It is, of course, not necessary that the

gears

10 and 16 be'of equal diameter so that their pitch circles, which obviously are both tangent to the tilt axis, can correlatedly be of differing diameter.

' The invention claimed is: I

l.'In combination with a single element type carrier having a hollow interior and having type characters located in columns and rows on its exterior surface, said carrier being mounted to be selectively tiltably and rotatably positioned to present selected type characters thereon for printing ata printing point, tilt and rotate positioning structure adapted to be received within said hollow interior of said type carrier and to mount said port means,

a drive gear and associated axle rotatably mounted on said support means, I

a tilt member pivotally mounted on said support means, v

and a driven gear and associated axle rotatably mounted on said tilt member,

said type carrier being mounted on said driyen gear axle after receiving said tilt and rotatestructure within its hollow interior, a

said mounting of said gears and tilt member on said support means being arranged to maintain said gears in constant mesh with their pitch circles tangent to the pivot axis of said tilt member.

2. In a machine having a single element type carrier characterized by a hollow interior and type characters arranged in rows and columns on its exterior surface, and mechanisms receivable within said hollow interior for mounting and for transmittingrotational and tilting motions to said single element type carrier to present a type character on a selected row and column for printing at a printing point comprising,

a support member having an end located within the hollow interior of said type carrier,

a tilt bridge pivotally mounted on the end of said support member within the hollow interior of said type carrier and tiltable about its pivot axis to present a selected row of type characters for printing at said printing point,

a rotate shaft rotatably supported in said tilt bridge type carrier, said positioning structure comprising supand coaxially supporting said type carrier thereon,

second gears tangent to the pivot axis of said tilt bridge. 3. The invention defined in claim 2, said first and second gears being crown gears.

4. The invention defined in claim 2, said single element type carrier being barrel shaped.

5. The invention recited in claim 2,

said printing point being defined by a stationary platen,

said support member being pivotal about an axis external to said type carrier to swing said single elewhere the axis of said rotate shaft is vertically oriented. l

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION Q PATENT NO. 3,825,102

DATED 1 July 23, 1974 INV ENTOR(S) 1 Herbert Decker It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In The Heading:

After item [21], insert --Foreign Application Priority Data December 18, 1969 Germany. .l9634776-- Signed and Scaled this Sixteenth D y f November 1976 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DANN Arlestmg' Office Commissioner oj'PalenIs and Trademarks

Claims

1. In combination with a single element type carrier having a hollow interior and having type characters located in columns and rows on its exterior surface, said carrier being mounted to be selectively tiltably and rotatably positioned to present selected type characters thereon for printing at a printing point, tilt and rotate positioning structure adapted to be received within said hollow interior of said type carrier and to mount said type carrier, said positioning structure comprising support means, a drive gear and associated axle rotatably mounted on said support means, a tilt member pivotally mounted on said support means, and a driven gear and associated axle rotatably mounted on said tilt member, said type carrier being mounted on said driven gear axle after receiving said tilt and rotate structure within its hollow interior, said mounting of said gears and tilt member on said support means being arranged to maintain said gears in constant mesh with their pitch circles tangent to the pivot axis of said tilt member.

2. In a machine having a single element type carrier characterized by a hollow interior and type characters arranged in rows and columns on its exterior surface, and mechanisms receivable within said hollow interior for mounting and for transmitting rotational and tilting motions to said single element type carrier to present a type character on a selected row and column for printing at a printing point comprising, a support member having an end located within the hollow interior of said type carrier, a tilt bridge pivotally mounted on the end of said support member within the hollow interior of said type carrier and tiltable about its pivot axis to present a selected row of type characters for printing at said printing point, a rotate shaft rotatably supported in said tilt bridge and coaxially supporting said type carrier thereon, a first gear coaxially secured to said rotate shaft within the interior of said type carrier, and means to transmit rotational movement to said type carrier to present a selected column of type characters for printing at said printing point including a second gear rotatably supported on said support member within said hollow interior of said type carrier and located to be in constant mesh with said first gear and with the pitch circles of said first and second gears tangent to the pivot axis of said tilt bridge.

3. The invention defined in claim 2, said first and second gears being crown gears.

5. The invention recited in claim 2, said printing point being defined by a stationary platen, said support member being pivotal about an axis external to said type carrier to swing said single element type carrier from a rest position toward said platen to print.

6. The invention recited in claim 5, said pivot axis of said tilt bridge being located opposite said platen from said rotate shaft and being located on a line extending through the printing point on the platen.

7. The invention defined in claim 3, the axis of rotation of said second gear having at least a predetermined inclination with respect to the axis of said rotate shaft when the type carrier has been tilted to a position where the axis of said rotate shaft is vertically oriented.