US3464532A - Keyboard pushbutton with character visible in depressed position - Google Patents

Description

L. TIBBETTS 3,464,532

KEYBOARD PUSH LiTTON WITH C AC VISIBLE Sept. 2, 1969* IN DEPRESSED P0 TIO Filed Aug. 30, 1967 V I so HO 120 loo 4 4 I00 I50 2.0 4 29,4

INVENTOR.

ERNEST L. TIBBETTS kfwf eg ATTORNEY.

United States Patent US. Cl. 197-98 9 Claims ABSTRACT OF THE DISCLOSURE The disclosure is of a pushbutton for displaying a character and for use in displaying a number in a calculating instrument. The pushbutton includes a fixed post having an upper end on which a character is printed or otherwise formed. A slidable sleeve member is slidably mounted on the post with its closed end parallel to and spaced above the end wall of the post. The sleeve member is made of a synthetic resinous material which is opaque when it is of a certain thickness, and is transparent when it is suitably thin. The side wall of the sleeve is sufficiently thick to be opaque, and the end wall is sufliciently thin so that, when it is depressed and it is placed close to the character, the character can be seen therethrough. When the sleeve is in its elevated position, the character on the fixed post cannot be seen.

The disclosure is also of a pushbutton assembly in which the sleeve of the pushbutton is provided with a wedge-shaped locking tab which engages an upper horizontal plate when the sleeve is in its elevated position. The assembly also includes a pivotable plate positioned between the upper plate and base plate for engaging the locking tab and holding the sleeve in its lowered position.

Background of the invention There are many types of pushbuttons known in the prior art for displaying characters such as numerals, letters, or the like. However, either the character is always clearly visible through the pushbutton, or, as in one known type of pushbutton, the character is dimly visible normally and is made clearly visible by a relatively complex combination of parts.

The present invention provides, in an extremely simple construction, .a pushbutton which includes a fixed post having an upper end which carries the character to be displayed. A slidable sleeve is mounted on the post, and the sleeve has a closed end which is used as a viewing window through which the character is to be viewed. Means are provided to hold the sleeve in an elevated position in which the character is not viewed or in a lowered position in which the character is viewed. To this end, the sleeve is made of a material, the transparency of which is determined by its thickness and the closed end or viewing window is sufficiently thin so that, when the sleeve is in its naised position, the character either cannot be seen at all, or it can be seen only dimly. However, when the sleeve is in its lowered position and the closed end is close to the character, the character can be seen clearly.

Description of the drawing In the drawing:

FIG. 1 is a sectional elevational view of a pushbutton and mounting assembly therefor according to the invention;

FIG. 2 is a sectional elevational view of the pushbutton of FIG. 1 as it appears in use; and

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FIG. 3 is a sectional elevational view of a modification of a portion of the invention; and

FIG. 4 is a plan view of the invention.

Description of the preferred embodiments The pushbutton 10 of the invention includes a fixed post 20 of a synthetic resinous material, metal, or the like, which is secured to a suitable support base 30 and includes an upper end wall 40. The character 50 to be viewed or displayed is formed on the upper end wall 40 in any suitable fashion, for example, by painting, spraying, silk-screening, etc. In a modified arrangement (FIG. 3), the character 25 is formed on resilient pad 42 of foam rubber or the like secured to the end wall 40 of post 20. The pushbutton 10 also includes a slidable sleeve 60 which comprises a tubular body 70 and a closed end or viewing window The sleeve 65 is slidably mounted on the post 20 and is held in a normally raised position by means of a spring which is threaded on the post 20 and rests on base plate 30'. The open lower end of the sleeve 60 rests on the spring 90. The sleeve 60 also includes a locking means in the form of a wedge-shaped tab 100, by means of which the sleeve is adapted to be locked in either its raised or lowered positions. The locking tab originates at a convenient location on the outer surface of sleeve 60 and expands outwardly and upwardly toward closed end 80, and it terminates in a flat surface a suitable distance below end 80. One or more tabs 100 may be provided, or the locking tab may be in the form of a single annular tab extending around the entire periphery of the sleeve.

The sleeve member is preferably made of a synthetic resinous material such as high density polyethylene, polyolefin, or the like which is opaque when suificiently thick and transparent when sufficiently thin. The side wall or main body 70 of the sleeve is thus preferably opaque. However, the closed end wall of the sleeve is a viewing window and is thus made relatively thin, for example, 45 to 50 mils, so that the viewer can see through it and so that, when the sleeve is depressed and the closed end 80 is close to or in contact with the end wall 40 of the post 20 (FIG. 2), the character 50 thereon can be viewed clearly through the end wall or viewing window 80 of the sleeve. When the sleeve is in its elevated position, the character either cannot be seen, or it can be seen only dimly.

In a typical arrangement for using one or more pushbuttons 10 in a calculating instrument or the like, an upper plate is provided spaced above the base plate 30 and having apertures for receiving the slidable sleeves 60. The arrangement of parts is such that, when a button is not in use, the surface 110 of locking tab 100 bears against the lower surface of upper plate 130, due to the upward force applied by spring 90. Another locking plate for locking the sleeve 60 in its lowered position comprises a pivot plate pivotally mounted on the base 30 by means of horizontal pin 132 suitably mounted and urged to the right, as seen in FIG. 1, by a spring 140. When the sleeve 60 is depressed, the ramp or tapered portion of tab 100 forces the pivot plate 130 to the left about its pivot point until the tab 100 is entirely beneath the upper locking edge 150* of plate 130. At this time, the spring urges the pivot plate 130 to the right, and spring 90 urges sleeve 60 upwardly to hold tab 100 in engagement with lip 150. The sleeve 60 is thus held in its lowered position, in which position the character 50 is clearly visible through its closed end 80.

What is claimed is:

1. A character displaying pushbutton assembly com- 3 prising a fixed post mounted on a base plate and having an upper end wall,

a character to be viewed formed on said upper end wall of said fixed post,

an apertured upper plate spaced above said base plate and having upper and lower surfaces,

a tubular sleeve slidably mounted on said post and positioned and slidably within an aperture in said apertured upper plate, said sleeve having an open end which receives said post and a closed end Which is spaced above the end wall of said post and above said upper plate,

a coil spring mounted on said post beneath said sleeve and normally maintaining said sleeve in an elevated non-displaying position with respect to said post,

said sleeve also being adapted to compress said springlike member and to assume a. lowered characterdisplaying position with respect to said post,

the side wall of said sleeve being opaque and the closed end of said sleeve being thin enough so that the character on said end wall of said post is clear- 1y visible through said closed end of said sleeve when the sleeve is in its lowered position and is not visible through said closed end when the sleeve is in its elevated non-displaying position,

said sleeve including a tubular side wall which carries a locking tab which bears against the lower surface of said apertured upper plate and thereby holds said sleeve in its elevated non-displaying position,

a second member pivotally mounted between said base plate and said apertured plate adjacent to said fixed post and positioned to be engaged by said tab when said sleeve is in its lowered position to lock said sleeve in its lowered position and pivotable to release said sleeve.

2. The apparatus defined in claim 1 wherein said second member comprises a pivot plate having a lower edge and an upper edge, said plate being pivotally mounted on said base on its lower edge whereby it can pivot toward and away from its pushbuttons about said lower edge, a spring secured to said pivot plate and urging it toward its pushbuttons, said upper edge of said pivot plate comprising a locking member and adapted to be engaged by said locking tab on a pushbutton, said locking tab being tapered and normally being positioned above said pivot plate, said locking tab being adapted to pivot said pivot plate away fromsaid sleeve as said sleeve is pushed downwardly whereby said locking tab can move vertically beneath said upper edge of said pivot plate and then said spring can draw said pivot plate back toward said sleeve whereby its upper edge can engage said locking tab beneath it.

3. A character displaying pushbutton comprising a fixed post having an upper end wall,

a character to be viewed formed on said upper end wall of said fixed post,

a slidable tubular sleeve slidably mounted on said post, said sleeve having an open end which receives said post and a closed end which is spaced above the end wall of said post,

a resilient, spring-like member in operative relation with said sleeve and normally maintaining said sleeve in an elevated non-displaying position with respect to said post,

said sleeve also being adapted to compress said springlike member and to assume a lowered characterdisplaying position with respect to said post,

said sleeve including a tubular side wall which carries a locking tab which is adapted to lock said sleeve in its elevated displaying position or in its lowered character-displaying position,

the side wall of said sleeve being opaque, and

the closed end of said sleeve being of the same material as said side wall and of such thickness that when the sleeve is in its elevated position and said closed end is remote from the end wall of said post, said closed end appears to be opaque and a character on the end wall of the post cannot be seen, and, when the sleeve is in its lowered position and its closed end is close to the end wall of said post, said closed end then appears to be transparent and a character on the end wall of the post can be seen.

4. The apparatus defined in claim 3 wherein said sleeve is made of high density polyethylene.

5. The pushbutton defined in claim 3 wherein said end wall and said side wall of said sleeve member are of one piece and of the same material, said end wall being thinner than said side wall to permit viewing or said character therethrough when said sleeve is in its lowered position.

6. The device defined in claim 3 wherein said sleeve is made of a synthetic resinous material whose transparency is related to its thickness, the material being opaque if it is sufficiently thick and transparent if it is sufficiently thin, the side wall of the sleeve being sufficiently thick to be opaque and the end wall being sufficiently thin to be transparent enough so that said character can be viewed therethrough when the sleeve is in its lowered position.

7. The device defined in claim 3 wherein said character is painted on said end wall of said fixed post.

8. The device defined in claim 3 wherein said character is silk-screened on said end wall of said fixed post.

9. The device defined in claim 3 wherein said locking tab tapers upwardly and outwardly from the wall of the sleeve toward the closed end thereof and terminates below said closed end in a generally flat surface,

said flat surface being adapted to bear against a plate to hold said sleeve in an elevated position, the taper of said tab permitting said sleeve to move downwardly past a cooperating locking plate whereby said flat surface can also engage said locking plate and hold said sleeve in its lowered position.

References Cited UNITED STATES PATENTS 1,286,769 12/1918 Quentell 235- XR 2,265,626 12/ 1941 Butler 235-145 2,642,226 6/1953 Luhn 235-445 3,237,591 3/1966 Pichel 197102 XR 3,244,847 4/1966 Erpel 197-98 XR 3,270,853 9/1966 Gerjets et a1. 197-98 3,311,210 3/1967 Peroni 19798 3,387,693 6/ 1968 Wirth 197--98 OTHER REFERENCES IBM Technical Disclosure Bulletin, vol. 6, No. 1. June 1963, p. 39, article by E. V. Weber entitled Changeable Keyboard Labeling and Coding.

EDGAR S. BURR, Primary Examiner US. 01. x11. 235-145; 197-102

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