US 3924724 A
Description (OCR text may contain errors)
Kerzel l l STRUCTURE FOR FACILITATING INTERCHANGE OF TYPING ELEMENTS  Inventor: Gunter Kerzel, Middelsfahr,
Germany  Assignee: Olympia Werke AG,
Wilhelmshaven, Germany  Filed: Mar. 19, 1975 [211 App]. No.: 560,085
 Foreign Application Priority Data Mar. 23, 1974 Germany 2414127  US. Cl 197/52; 206/804  Int. Cl. B41J 1/60  Field of Search 197/52; 206/804, 472, 403,
 References Cited UNITED STATES PATENTS 2,969,864 l/l961 Holgate 197/52 3,001,628 9/1961 Rice, Jr 197/52 3,307,677 3/1967 Frank et al. 197/52 3,576,340 4/1971 Jones et al. 206/444 X 3,635,608 1/1972 Crouch et a1. 206/444 3,753,490 8/1973 Mowrey l l 206/444 3,800,934 4/1974 Decker.... 197/52 3,826,345 6/1974 Miller 197/52 OTHER PUBLICATIONS Spherical Type Element Holding Device, R. D. Mathews, IBM Tech. Disc. Bulletin, Vol. 13, No. 1, June 1970.
One-Piece Chipboard Typehead Box, Dunning et al., IBM Tech. Disc. Bulletin, Vol. 17, No. 1, June 1974.
Primary Examiner-Edgar S. Burr Assistant Examiner-Paul J. Hirsch Attorney, Agent, or FirmSpencer & Kaye  ABSTRACT In order to facilitate the interchange of typing elements of the type having a cap at their top and arranged to be interchangeably installed on the element post of a typing machine, and to be stored in a container when not on the machine, the element being provided, in the vicinity of its upper extremity and below the cap, with a locking device movable between a locking position in which it fastens the element to the post and an unlocking position in which it permits the element to be lifted from the post, there is provided a member which defines a cover arranged to close the container in a hermetically sealed manner, and the cover is provided with a coupling unit which serves to connect the cover to the typing element cap while holding the locking device in its unlocking position, and a control member which can be actuated to disconnect the cover from the cap in order to permit the cover to be removed from the typing element, the locking device being enabled to move to its locking position upon removal of the cover from the cap.
6 Claims, 4 Drawing Figures 3,924,724 [451 Dec. 9, 1975 U.S. Patent Dec. 9, 1975 Sheet 1 of2 3,924,724
U.S. Patent Dec. 9, 1975 Sheet 2 of2 3,924,724
STRUCTURE FOR FACILITATING INTERCHANGE OF TYPING ELEMENTS BACKGROUND OF THE INVENTION The present invention relates to an apparatus for replacing a capped typing element for typewriters or sim ilar office machines of the type in which the typing element is releasably fastened to the element post of the machine by means of a locking device disposed on its top surface, the typing element being stored prior to installation in a cup-shaped container having a hermetically sealed cover.
In printing mechanisms of typewriters and similar machines it is important that the typing element be easily exchangeable because there is often the necessity to frequently change over to foreign languages having different characters, to other types of script, or to special formula symbols. In such a change, the typing element should be easily removable from, and insertable into, its mount without there existing the danger of dropping the typing element or of soiling the fingers with printing ink.
Austrian Pat. No. 270,699 discloses a typing element with a lever handle which is pivotally mounted in a cap. This lever handle acts via a cam surface disposed thereon on a wire spring which is also disposed in the cap and engages in a groove in the element post. Complicated process steps are required to produce the lever handle of the known arrangement, and particularly to produce the cam surfaces. These cam surfaces are also subject to increased wear because the free ends of the spring are in continuous frictional contact with the cam surfaces. Thus, these cam surfaces must be made of a hardenable material and this involves additional expenditures.
The known locking device further requires a certain dexterity on the part of the operator since pivoting of the lever handle is effected against the continuously increasing force of the wire spring and must thus be performed with care in order to prevent the thumb or a tinger from slipping off the lever handle. If this were to occur, the lever handle, which is under the force of the spring, would flip back into its starting position.
This known lever handle does prevent contact with the typing element surface during placement onto, and removal from, its mount, but not when the element must be taken out of its box. In the box, the lever handle of the interchangeable typing element, which has a dirty surface, is in the closed position. In order to place this typing element onto the mount of the element post, it is necessary to tilt up the lever handle. Since this is effected against the force of a spring, the typing element must be supported by placing the fingers against its surface. The danger of soiling the fingers with the printing ink thus remains.
SUMMARY OF THE INVENTION It is an object of the invention to provide a typing element which the machine operator can exchange without special dexterity being required and without the danger of soiling their fingers.
These and other objects of the invention are achieved in a device of the type described above by the provision of a detent coupling which is under spring pressure and which connects the cover of the container with the cap of the typing element to permit removal of the element from, or installation on, the element post and by arranging the locking device so that it can be manually brought into two positions by means of the cover for the purpose of locking or releasing the typing element.
The apparatus according to the present invention permits safe and easy exchanging of the typing element without contact with the surface bearing the type characters. The removal and placement and the release and fastening of the typing element on its mount is effected by means of the already present cover of the storage container for the typing element. Thus no additional auxiliary means are required.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a preferred embodiment of the invention.
FIG. 2 is a cross-sectional view of the typing element and the container cover of FIG. 1 in place on an element post.
FIG. 3 is a view similar to that of FIG. 2 showing the elements of FIG. 2 in a different state.
FIG. 4 is a plan view of the locking device of the preferred embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a cup-shaped container 1 with a hermetic sealing locking cover 3 for a typing element, for example a spherical typing ball 5. The element 5 may of course also have another shape, for example a cylindrical shape. The spherical typing ball 5 is firmly and permanently connected with a cap 7 and is constructed to be form-fittingly and releasably connected, by means of a bearing sleeve 9 disposed in its upper portion, as shown in FIGS. 2 and 3, with an element post 11 of the setting drive of a typewriter.
The element 5 is locked in its position by means of a locking device which is disposed on its topside and below cap 7. Post 11 and the structure for controlling its movements are already known in the art. This locking device includes, for example as shown in FIG. 4, three spring-tensioned blocking slides 13, 15 and 17 which are angularly spaced from one another, and which are guided into corresponding transverse slits 19, 21 and 23 in the bearing sleeve 9 so as to engage, through the sleeve 9, in an annular groove 25 of element post 11.
By means of a common spring ring 27, the blocking edges 29, 31 and 33 of theblocking slides 13, 15 and 17, respectively, are urged into groove 25, these edges being in constant contact with ring 27 by means of bent tongues 35, 37 and 39, respectively.
In order to mount the spherical typing ball 5 on element post 11 without axial play, the groove surface 26 of groove 25 which cooperates with blocking edges 29, 31 and 33 is given a conical shape. Thus the lower surface 41 of the bearing sleeve 9 is always pressed without play against a radial extension 43 of the element pull 1 1. Of course, this mounting without play can also be realized by giving a conical configuration to the blocking edges 29, 31 and 33 of the blocking slides 13, 15 and 17, respectively.
The removal of the typing ball 5 from element post 11, or the installation of ball 5 on post 1 1, is made possible by cover 3 of container 1. For this purpose, cover 3 is provided with a detent coupling which is maintained under spring pressure and which can be connected with the cap 7 of typehead 5. This detent coupling includes a plurality of, for example three, fingers 45 which are angularly offset by 120 from one another and which are disposed on the inside of cover 3. These fingers can be pushed into and through appropriately designed recesses 51 in cap 7 of the ball 5 and can be held fast to cap 7 by means of detent ridges 57 which are carried by resilient arms 63 integral with fingers 45 and which normally project into the region between cap 7 and sleeve 9.
The connection between the ball 5 and cover 3 can be controlled by a button 77 which is disposed in the center of cover 3. This button 77 is mounted to be axially movable in a portion of cover 3 which is provided with a circular gripping edge 79. The free ends 81 of fingers 45 in cover 3 are provided with tapered, conically rounded edges 87 which cooperate with the bent tongues 35, 37 and 39 of the blocking slides l3, l5 and 17, respectively, in order to bring the blocking slides 13, 15 and 17 into their unlocked position when the cover 3 and cap 7 are coupled together and into their locked position when the detent coupling between tongues 35, 37 and 39 and fingers 45 is released.
The coupling of element post 11 with typing element 5 is effected via a pin-slot connection. For this purpose the bearing sleeve 9 is provided with two slits 2 and 4, of respectively different widths, which can be coupled by means of a pin 6 held in post 11 and having ends 8 and of respectively different diameters adapted to the widths of the slits. The respectively different diameters of ends 8 and 10 of pin 6 and the corresponding respectively different widths of slits 2 and 4 are necessary in order to assure that the typing element 5 will be installed in the proper direction.
The arrangement according to the present invention operates as follows:
In order to install the spherical typing ball 5 into a typewriter, it is taken together with its cover 3 from the cup-shaped container 1 of FIG. 1 and placed onto the element post 11. Then cover 3 and element 5 are rotated until the ends 8 and 10 of pin 6 are disposed above their associated slits 2 and 4. The element 5 and its cover 3 can now be pushed downwardly until the lower surface 41 of the bearing sleeve 9 comes to rest on the extension 43 of the element post 11.
Now button 77 is pressed downwardly in the direction of the arrow in FIG. 2 so that a convexly curved spring disc 69 is brought into approximately its flattened, or extended, position. Thus, the resilient arms 63 with their detent ridges 57 are pressed outwardly so that the detent coupling is released.
Now cover 3 is free to be pulled upwardly'via its gripping edge 79 into the position shown in FIG. 3. Thus, the free ends 81 of fingers 45 release the blocking slides 13, 15 and 17 and the latter are urged by the force of spring ring 27 with their blocking edges 29, 31 and 33 against the conical surface 26 of groove 25 of the ele' ment post 11. Due to the cooperation of the conical surface 26 of groove 25 with the blocking edges 29, 31 and 33, the typing element becomes fastened without axial play on element post 11. Cover 3 is then put back on container 1.
If the typehead 5 is now to be removed again from element post 11, cover 3 is again picked up and fingers 45 are placed into the corresponding recesses 51 in cap 7 of element 5. The cover 3 is pressed downwardly until the free ends 81 of fingers 45 come to rest on the extension 43 of the element post 1 1. Thus the free ends 81 of fingers 45 press with their concial edges 87 onto the bent tongues 35, 37 and 39 of the blocking slides 13, 15
and 17 in such a way that the latter are brought into the released position in opposition to the force of spring ring 27. Moreover, the detent ridges 57 engage between cap 7 and sleeve 9 when cover 3 is being pressed down. Now the typing ball 5 can be easily lifted together with, and with the aid of, cover 3 without requiring contact with the ink covered surface of the ball. The ball 5 is then placed back into container 1. Thus the operator of the machine need not have any special dexterity to exchange the typing ball 5 and soiling of the fingers is virtually impossible in this type of exchange process.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims; in particular, the described detent coupling betweenthe cover and the cap of the typehead as well as the locking devices between the typehead and the type carrier shaft can be modified.
What is claimed is:
1. In combination: a typing element having a cap at its top and arranged to be interchangeably installed on the element post of a typing machine and to be stored in a container when not on the machine, the element being provided, in the vicinity of its upper extremity and below the cap, with a locking device movable between a locking position in which it fastens the element to the post and an unlocking position in which it permits the element to be lifted from the post; and a member defining a cover arranged to close the container in a hermetically sealed manner, wherein the improvement comprises: detent coupling means arranged to selectively connect said cover to said cap for permitting said typing element to be moved as a unit with said cover; spring means normally maintaining said detent coupling means in the position for creating such connection between said cover and said cap; and latch means carried by said cover for holding said locking means in said unlocking position when said cover is connected to said cap and for enabling said locking device to move to said locking position when said cover is separated from said cap.
2. An arrangement as defined in claim 1 wherein said cap is provided with a plurality of openings, and said latch means comprise a plurality of fingers projecting from that side of said cover which faces toward the interior of said container when closing said container, said fingers being arranged to engage through respective ones of said openings, and said detent coupling means comprise a plurality of detent ridges each carried by a respective one of said fingers and extending laterally past the border of a respective opening to thus selectively connect said cover to said cap.
3. An arrangement as defined in claim 2 wherein said spring means comprise a plurality of resilient arms each carried by a respective one of said fingers and each carrying a respective one of said detent ridges, and said detent coupling means further comprise a convexly curved spring disc operatively associated with said resilient arms in a manner such that flattening of said disc moves said ridges in a direction to release the connection between said cover and said cap, and a push button located at the center of said cover and operatively associated with said disc in such a manner that pressure on said button serves to move said disc in the direction of flattening.
4. An arrangement as defined in claim 3 wherein said locking device comprises a plurality of blocking slides presenting blocking edges arranged, when said typing element is installed on the element post of a typing machine, to be disposed concentrically to an annular locking groove provided on the element post and to engage in such locking groove to define the locking position of said device, each said blocking slide being operatively associated with the extremity of a respective one of said fingers of said latch means, said extremities of said fingers bringing said blocking slides into a position in which said blocking edges clear such groove, constituting the unlocking position of said device, when said cover is connected to said cap, and permitting said blocking slides to move to the locking position of said device when said cover is separated from said cap.
5. An arrangement as defined in claim 3 further comprising an element post on which said typing element is to be installed, said post having an annular locking groove presenting a conical configuration in the direction of movement of said locking device, and said locking device comprises a plurality of blocking slides presenting blocking edges disposed concentrically to said locking groove when said element is on said post and arranged to engage in said locking groove to define the locking position of said device, each said blocking slide being operatively associated with the extremity of a respective one of said fingers of said latch means, said extremities of said fingers bringing said blocking slides into a position in which said blocking edges clear said locking groove, constituting the unlocking position of said device, when said cover is connected to said cap, and permitting said blocking slides to move to the looking position of said device when said cover is separated from said cap.
6. An arrangement as defined in claim 4 wherein said locking device further comprises a common spring ring connected to all of said blocking slides for urging them into the locking position of said device.