US 3648394 A
A keytop for the keys of business machines, the keytop being of sectional construction comprising a base, a removable transparent cap and a removable key identification marker held by and between the base and the removable cap.
Description (OCR text may contain errors)
United States Patent Hepner 1 Mar. 14, 11972  KEYTOP STRUCTURE FOREIGN PATENTS OR APPLICATIONS  Inventor: Neal Hepner, Birmingham, Mich. 986,818 4/1951 France ..197/ 102  Assignee: Burroughs Corporafion, Dem), Mich. 423,835 5/1967 Switzerland ..197/ 102  Filed: Jan. 12, 1970 Primary ExaminerRobert W. Michell Attorney-Kenneth L. Miller and Edwin W. Uren  Appl. No.: 1,997
 ABSTRACT  U.S.Cl ..40/331, 197/102 A ke ytop for the keys of busmess machines, the keytop being  lllll. Cl ..G09f 3/08 of Sectional construction comprising a base a removable  Field of Search ..40/331, 332, 315, 319, 2; transparent cap and a removable key id ifi i marker 197/102, 103, 104; 235/145, 146; 178/110 held by and between the base and the removable cap.
 References Cited 3 Claims, 5 Drawing Figures UNITED STATES PATENTS Dronberger ..40/331 X PATENTEDMAR 14 I972 3,6835% 20 h; INVENTOR. 54 22 3 NEAL HEPMERi l8 BY ATTORNEY KEYTOPSTRUCTURE SUMMARY OF THE INVENTION The invention resides in the provision of a sectionally constructed keytop such that the removable key identification marker can be readily replaced.
In certain electronic accounting machines, the programming of the machine is designed so that it can be readily altered to provide a program or programs other than the basic programs. For example, electrical connections provided in such machines make it possible to initiate an altered program to achieve a certain desired machine function by the depression of an alpha key or a numeric key, normally used for typing. However, when such an altered program is effected, the marker or symbol of the converted alpha or numeric key, as the case may be, is not indicative of the function performed by depression of the key which is, of course, confusing and inconvenient to the operator.
Accordingly, the principal object of the invention is to provide for holding a removable key identification marker between a keytop base and a transparent cap by readily releasable snap-in fasteners received within the keytop base.
In the drawings:
FIG. 1 is an exploded perspective view of the keytop structure, embodying features of the invention;
FIG. 2 is a horizontal sectional view, taken along the line 2-2 of FIG. 4;
FIG. 3 is a vertical sectional view, taken along the line 33 of FIG. 4;
FIG. 4 is a vertical sectional view, taken along line 44 of FIG. 3; and
FIG. 5 is a fragmentary vertical sectional view.
With reference to the drawings, the keytop comprises in general a base 12, a transparent cap 14 and a key identification marker 16. The cap 14 is releasably attached to the base 12 and the key identification marker 16 is held by and between the base and the cap. The base 12 is to be secured onto a stem 18 of a key of a business machine keyboard (not shown).
The base 12 is preferably made of a suitable opaque plastic material which may be molded in the form of a truncated quadrilateral pyramid. The sides of the base 12, as at 20 and 21, surround a centrally located web 22 which depends from the top of the base, the web having a vertical aperture to receive an upper end portion of the keystem 18. Through the top of the base 12 there is provided a pair of vertically extending apertures 24 to receive respectively a pair of latch members or snap-in fasteners 26 provided on the underside of the cap 14. The apertures 24 are oppositely disposed respectively to the opposite sides 20 of the base and open through the sides 20, recessing the sidewalls, as at 27. The apertures 24 are preferably rectangular, as seen in cross section, and are defined in part by parallel end surfaces 28 of the rectangular apertures to provide a pilot for the latch members 26. The recesses, as at 27, formed in opposite sides 20 of the base 12 provide access for digitally gripping the closure member portion of the cap 14 to facilitate the manual removal of the latter, thereby freeing the key identification marker 16.
Preferably the removable cap 14 is formed by a molding operation and may be made of any suitable transparent plastic material, such as polycarbonate, or an acrylic plastic, such as LUCITE. The cap 14 and the snap-in fasteners 26 are molded integrally, the fasteners being oppositely disposed respectively adjacent opposite ones of opposite edges of the cap. At these edges, the cap 14 is formed with depending closure members or lugs 30 which position in the apertures 24 and function as guide members to align the cap properly with the base 12. Integral with the lugs 30 and offset inwardly from the edges of the cap 14 are downwardly extending portions 32 having 0pposite parallel edges which fit into the apertures 24, and depending downwardly from each portion 32 there is a pair of diverging resilient or spring fingers 34. The opposite outer edges of the fingers 34 engagle diverging end surfaces 36 of the apertures 24 to releasab y old the cap 14 to the base 12.
Thus, the diverging end surfaces 36 of the apertures function as keepers for the fingers 34. It will be apparent that when the fingers 34 enter the restricting pilot defined by the surfaces 28, the fingers 34 are flexed toward each other and are tensioned such that when they clear the pilot the tensioned fingers flex outwardly against the diverging end surfaces 36.
The key identification marker 16 is a thin slip of sheeting which may be made of any suitable material including paper and has two oppositely disposed pairs of ears, each pair defining a notch 38, edges to receive the lugs 30 of the cap, the effective orientation of the marker between the cap and base members being thereby defined. A symbol for identifying the function performed by depression of the key is provided and, in the present instance is INT an abbreviation for Interest. This, of course, indicates to the operator that by depression of the key a machine operation may be initiated to calculate the interest due in a particular business transaction. Preferably, the normal function of the key is identified on the front face of the key top base 12 by a symbol which is indicated by the letter T.
What is claimed is:
1. A sectionally constructed keytop structure for use in business machine keyboards comprising:
a transparent cap member having resilient latch elements extending therefrom, said latch eiements being two oppositely disposed pairs of diverging spring fingers;
a removable key identification marker; and
a base member securable to a keyboard keystem and having a pair of oppositely disposed apertured recesses defined in part by oppositely disposed diverging surfaces constituting keepers, said spring fingers being removably insertable into said apertured recesses and being squeezably displaced by said keepers for releasable retainment therebetween, said cap member being thereby held effectively against said base member, said key identification marker being held by and between said cap and base members, said recesses additionally providing access for digitally gripping effective portions of said cap member, thereby facilitating the manual removal of said cap member from said base member.
2. A sectionally constructed keytop structure as defined by claim 1 wherein said removable key identification marker has two oppositely disposed pairs of ears, each pair defining a notch to receive an associated pair of said spring fingers, the effective orientation of said marker between said cap member and said base member being thereby defined.
3. A sectionally constructed keytop structure as defined by claim 2 wherein said pairs of spring fingers are laterally offset inwardly from the periphery of said cap member.