Hand held calculator having a retractable cover

A portable, hand held, electronic calculator assembly has a retractable cover slidably mounted to a calculator. The calculator has a front with a keypad and display, and a back. The cover has an inner surface and an exposed outer surface. The cover is movable relative to the calculator between a first position where the cover inner surface is juxtaposed to the calculator front, thereby protecting the keypad and display, and a second position where the cover inner surface is juxtaposed to the calculator back.

TECHNICAL FIELD 
This invention relates to portable hand held calculators, and more 
particularly, to covers and supports for such calculators. 
BACKGROUND OF THE INVENTION 
A portable, hand held, electronic calculator is designed to be held with 
one hand or supported on a desk top. The calculator has a flat panel 
display positioned above a keypad. The display is commonly made of glass 
or plastic which can be scratched or broken. A separate protective casing 
is typically used to shelter the display and keypad when the calculator is 
not in use. Unfortunately, the casing can be misplaced by the user or 
otherwise lost, leaving the calculator vulnerable to debris, scraping, 
damage, or inadvertent activation of the "ON" button which, in some 
calculators, drains the battery supply. 
SUMMARY OF THE INVENTION 
According to one aspect of this invention, a portable hand held calculator 
assembly having an integrated calculator and protective covering is 
provided. The calculator has a front with a keypad and display, and a 
back. A retractable cover is slidably coupled to the calculator to protect 
the keypad and display. The cover is movable between a first position 
where its inner surface is juxtaposed to the calculator front, thereby 
protecting the keypad and display, and a second position where its inner 
surface is juxtaposed to the calculator back. 
According to another aspect, a pair of interconnecting pins are used to 
slidably couple the cover to the calculator. The pins are integrally 
formed with the cover and slidably mounted within guide tracks formed in 
opposing sides of the calculator. As the cover is moved from the first 
position to an intermediate position, the pins slide in their respective 
guide tracks toward either the top or bottom ends of the calculator. At 
the intermediate position, the cover is pivoted about the end of the 
calculator. The cover can then be moved from the intermediate position to 
the second position whereby the pins slide in their respective guide 
tracks away from the end of the calculator back toward the middle. The 
cover is then situated in a retracted, stored position. 
According to yet another aspect of this invention, the cover can be used to 
prop the calculator at various angles when situated at the intermediate or 
second positions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
This disclosure of the invention is submitted in furtherance of the 
constitutional purposes of the U.S. Patent Laws "to promote the progress 
of science and useful arts" (Article 1, Section 8). 
FIGS. 1 and 2 show a portable, hand held, electronic calculator assembly 20 
that is constructed according to this invention. Calculator assembly 20 
includes a calculator 22 and a retractable cover 24 slidably coupled to 
the calculator. Calculator 22 comprises a keypad 26 having individually 
actuatable keys arranged in a customary pattern, and a visual display 28 
such as an LCD flat panel display. An "ON" button to activate the 
calculator is provided as part of the keypad. The calculator 22 further 
includes electronics coupled to the keypad and visual display, as well as 
an IC microprocessor chip which performs the calculating functions and a 
power supply (none of which are shown). Calculator 22 is of conventional 
design with respect to its calculator functionality and operation. 
Calculator 22 has an upper face or front 30, which includes the keypad 26 
and display 28, and a lower face or back 32 (not numbered in FIGS. 1 and 
2, but shown in FIGS. 5-9). Calculator 22 also includes, a top end 34, a 
bottom end 36, and opposing sides 38 and 39 (where only side 38 is shown 
in FIGS. 1 and 2). 
Cover 24 is movable relative to calculator 22 between a first, closed 
position where the cover overlies the calculator front (FIG. 1) and a 
second, retracted position where the cover is aligned along the calculator 
back (FIG. 2). When situated in the closed position, cover 24 overlies and 
protects substantially all of the calculator front 30. Preferably, cover 
24 has a length almost equal to the length of the calculator, as shown. In 
this manner, the cover has a length effective to shield both the keypad 26 
and display 28 when the cover is in its closed position (FIG. 1). The 
cover is preferably formed of a hard material to thereby prevent scraping 
or damage to the display, debris from the keypad, or inadvertent 
activation of the "ON" button of the keypad. 
With additional reference to FIGS. 3 and 4, cover 24 has a panel 40, an 
inner surface 42, an exposed outer surface 44, opposing ends 46 and 48, 
and opposing side walls 50 and 52. Panel 40 is substantially flat, but 
with a very slight outward bow. It provides the protective shielding of 
the keypad and display. Side walls 50 and 52 extend perpendicularly from 
panel 40 down over sides 38 and 39, respectively, of calculator 22. 
Calculator assembly 20 has an interconnection means for slidably coupling 
retractable cover 24 to calculator 22. The interconnection means enables 
movement of the cover from the closed position (FIG. 1) to the retracted 
open position (FIG. 2) in a manner that maintains the inner surface 42 of 
cover 24 in juxtaposition with the calculator 22 throughout the movement. 
In a preferred implementation, according to one aspect of this invention, 
the interconnection means comprises a pair of interconnecting pins 60 and 
62 that are connected to the cover 24 and slidably mounted within 
respective guide tracks 64 and 65 formed in respective sides 38 and 39 of 
calculator 22. 
Pins 60 and 62 are connected to inner surfaces of the cover side walls 50 
and 52 approximately midway between opposing cover ends 46 and 48. Pins 60 
and 62 are coaxially aligned along pin axis 68, substantially 
perpendicular to an elongated medial axis 70 defined by the calculator 
(FIG. 3). The pins project inwardly toward one another to slidably mount 
within guide tracks 64 (FIG. 4). Pins 60 and 62 include respective 
oversized, circular heads 61 and 63 which retain the pins laterally within 
the guide tracks and facilitate smooth longitudinal movement within the 
tracks. Preferably, pins 60 and 62 and cover 22 are integrally formed of a 
single unit of hard material, such as hard plastic. 
As a preferred construction, calculator 22 has a calculator body comprised 
of an upper casing 72 and a lower casing 74 which are joined together 
(FIGS. 1, 2, and 3). The joint between the upper and lower body casings 
form guide tracks 64 and 65 which run along the sides 38 and 39, and 
between the top and bottom ends 34 and 36 of calculator 22. During 
assembly, the cover pins are first positioned on the lower guide rail of 
lower casing 74. The upper casing 72 is then snapped or otherwise mounted 
onto the lower casing 74 to provide the upper guide rail, thereby 
completing the guide tracks 64 and 65. 
Cover 24 includes a raised support member 80 which is used to prop the 
calculator at an inclined angle when the cover is at the retracted 
position (FIG. 2). Support member 80 is mounted to outer surface 44 at end 
48 of the cover. Support member 80 is preferably formed of a 
skid-resistant material, such as rubber or elastomer, to resist 
displacement of the calculator assembly when laying on a desk top. 
FIGS. 5-9 show one possible technique for retracting the cover. In FIG. 5, 
the cover 24 is situated at a first, closed position where it overlies 
both the keypad and display to shield them from unwanted debris and 
damage. At this position, the cover inner surface 42 is juxtaposed with 
the calculator front. Raised detents or bumps 90 (FIG. 6) are provided 
within the guide tracks at the middle of the calculator to positionally 
urge the pins to selected locations which coincide with the closed cover 
position. These bumps are of sufficient size to retain the pins at the 
middle of the calculator until a force applied by the user overcomes the 
mechanical urging induced by the bumps. 
To open, the cover is first moved from its closed position toward an 
intermediate position at one end of the calculator (FIG. 6). For purposes 
of discussion, assume that the cover 24 is moved to the top end 34 of the 
calculator 22. The pins 60, 62 are pushed past the raised bumps 90 and 
slid within guide tracks 64 toward the top end 34. A second set of raised 
detents 92 (see FIG. 5) can be provided at the top end of the guide tracks 
to temporarily secure the pins in this intermediate position. 
At the intermediate position, the cover 24 is pivoted about the top end 34 
from an initial parallel position where the cover overlies the calculator 
front (FIG. 6), through a substantially perpendicular position relative to 
the calculator (FIG. 7), to a subsequent parallel position where the 
calculator is aligned along the back (FIG. 8). During this pivotal 
movement, the pins remain station within the track guides and held at the 
top end by the raised bumps 92 in the guide tracks. 
The cover is then moved from the intermediate position of FIG. 8 to the 
second, retracted position of FIG. 9. The pins 60, 62 are pushed past the 
raised bumps 92 and slid within guide tracks 64 away from top end 34 back 
to the middle of the calculator where the pins are once again retained by 
detents 90. At the retracted position, the cover inner surface 42 is 
juxtaposed with the calculator back. To close the cover, the process of 
FIGS. 5-9 is simply reversed. 
It is noted that the cover inner surface 42 remains in juxtaposition with 
the calculator throughout the entire movement between the closed and 
retracted positions. It is further noted that the cover can be retracted 
or closed by pivoting the cover about the bottom end 36 in a like manner. 
FIGS. 10 and 11 show two alternative propping angles that can be achieved 
by the cover, in addition to the propping angle shown in FIG. 2. In FIG. 
10, the cover is at its intermediate position and approximately 
perpendicular to the calculator. The lower half of the cover is used to 
prop the calculator at a relatively steep incline in comparison to the 
moderately inclined angle of FIG. 2. By contrast, FIG. 11 shows the cover 
in an extended position along the back of the calculator. Here, the 
incline angle is relatively modest compared to both incline angles of 
FIGS. 2 and 10. Other angles of incline are also possible. 
The calculator assembly of this invention is advantageous in that it 
provides a protective cover that can be retracted to an out-of-the-way 
position for hand operation, or used as a support to prop the calculator 
at an angle when set on a desk top. The cover remains permanently attached 
to the calculator, thereby eliminating the problems associated with covers 
being misplaced, lost or stolen. 
In compliance with the statute, the invention has been described in 
language more or less specific as to structural and methodical features. 
It is to be understood, however, that the invention is not limited to the 
specific features shown and described, since the means herein disclosed 
comprise preferred forms of putting the invention into effect. The 
invention is, therefore, claimed in any of its forms or modifications 
within the proper scope of the appended claims appropriately interpreted 
in accordance with the doctrine of equivalents.