Joystick assembly

A joystick assembly for converting push-button keys to joystick actuation comprises a handle and a multi-arm member, the multi-arm member includes arms located for contact with keys of a computer keyboard, each arm having a depending end for engaging a respective key. The handle inserts perpendicularly through the multi-arm member through a central aperture and is adjustable perpendicularly with respect to the keyboard. Apparatus is incorporated for fastening an end of the handle to a central key of a keyboard.

BACKGROUND OF THE INVENTION 
The present invention relates to joystick assemblies and, more 
particularly, to a joystick assembly for use with a keyboard for 
converting movement of a joystick handle to actuation of selected keys of 
a keyboard. 
Computers are generally provided with a keyboard having at least one set of 
keys arranged in the format of a typewriter keyboard. To one side of this 
set of keys, there is normally provided a "numerical key pad" arranged in 
a common calculator arrangement, i.e., a 3.times.3 pattern for keys 
corresponding to numbers 1-9. These numerical keys, which are essentially 
push button switches, have also been adapted to control other functions of 
the computer. The keys corresponding to numerals 2, 4, 6 and 8 are also 
utilized as cursor control keys for moving a position cursor on a computer 
display by one increment, e.g., up or down one line and left or right one 
position. The keys corresponding to numerals 3 and 9 are also utilized for 
moving the cursor up and down one page at a time. The keys corresponding 
to numerals 1 and 7 also serve as "end" and "home" keys for moving a 
cursor to end and home positions in one move. 
It is expected that a computer operator will manipulate these cursor 
control keys in the same manner as a typist, i.e., by manually depressing 
a desired key. However, computers are often used in other modes than word 
processing. In particular, computers are frequently used to create 
drawings using various CAD programs and more frequently to play various 
computer games. In these latter modes, movement of the cursor is a primary 
concern and it is desirable to be able to make such movements without 
observing finger positions on the keys. While some applications require 
cursor movements to be controlled by a "mouse" attachment, others, 
particularly games, allow joysticks to be used. The problem with both the 
mouse and joystick is that they require separate input cables to the 
computer and additional hardware for accepting external input. 
More recently, it has been proposed to construct a joystick which can be 
attached to an ordinary keyboard and positioned such that movement of the 
joystick actuates the cursor control keys. One such joystick is shown in 
U.S. Pat. No. 4,575,591. The joystick described in this patent requires a 
panel-like base member attachable to the keyboard frame with a joystick 
handle attached to the base member and spaced from the keys. A universal 
mount is attached to the base member and engages the lower end of the 
handle to allow handle movement in any tiltable direction. Actuating arms 
are mounted on the base member such that they can be engaged by movement 
of the handle to force them into contact with the keys. In addition to the 
relative complexity of this joystick attachment, a relatively large base 
member is required to be attached to the keyboard. Furthermore, while the 
above described patent disclosed an attachment for a computer keyboard, it 
will be recognized that other devices, such as hand-held games, have 
cursor control keys which would be desirably actuated from a joystick if 
such could be provided. 
SUMMARY OF THE INVENTION 
It is a general object of the present invention to provide a relatively 
simple joystick for attachment to a keyboard for operating cursor control 
keys. 
It is a more specific object of the invention to provide a joystick for 
operating cursor control keys which can be easily attached and removed and 
has no separately movable parts during use. 
The above and other objects, features and advantages are attained in a 
joystick assembly comprising a handle, a multi-arm member attached to a 
lower portion of the handle and a base member which is adhesively fixed to 
a center key in a cursor control keypad. The lower end of the handle is 
removably attachable to the base member and is formed of a reduced 
diameter. The handle is constructed of a material that allows flexing of 
the reduced diameter end. The multi-arm member comprises plural outwardly 
extending arms terminating in downward extending ends. Movement of the 
handle causes the arms to engage selected ones of the keys. Preferably, 
the arm ends are of different lengths to accommodate the differing 
relative heights of keys on a keyboard.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 illustrates one form of the present invention depicting a joystick 
assembly 10 mounted on a numerical keypad section of a keyboard 12 and 
viewed from the keyboard. The keyboard is assumed to a type 5060 or 5151 
keyboard commonly used in computer systems. The computer and computer 
display are not illustrated but will be recognized to be an inherent part 
of an operating system. The joystick assembly 10 includes a multi-arm 
member 14 having circumferentially spaced, radially extending to L-shaped 
arms 16 terminating in downwardly extending ends 18 of various lengths so 
that terminal ends 20 are spaced an equidistance from keys 22 to be 
actuated. The member 14 incorporates a center aperture 24 for receiving a 
handle 26. The aperture 24 and handle 26 are each sized to form a non-slip 
union of the member 14 to the handle 26. 
FIG. 2 is a top view of the joystick assembly of FIG. 1 positioned on a 
central key 28 of keyboard 12 with the arms 16 of the multi-arm member 14 
and their respective depending ends 18 in position above cursor control 
keys 22. The handle 26 is shown as it protrudes vertically upward through 
the multi-arm member 14. 
FIG. 3 is a cross-sectional view of the joystick assembly FIG. 1. The 
handle 26 may include an enlarged upper portion 30 suitable for gripping 
by a user. At the area indicated at 32, the handle is sized to fit snugly 
within aperture 24 in multi-arm member 14. The fit between handle 26 and 
member 14 may be a sliding fit with both handle 26 and aperture 24 being 
concentrically circular or both may be provided with locking means, such 
as a tab and slot, to prevent relative rotational movement. Alternatively, 
the handle and aperture could each be threaded. 
The joystick assembly is preferably attached in position over the cursor 
control keys using a mounting means 34 attachable to the center key, 
usually the number 5 key. The mounting means 34, in one form, comprises a 
relatively thin, plastic pad 36 having a shape conforming to the size and 
shape of the top surface of the center key. An adhesive is applied to a 
lower side of the pad 36 allowing it to be adhered to the top surface of 
the center key. Double-sided tape 36A may be used for this purpose (see 
FIG. 5). The pad 36 may be formed with a center aperture 38 for receiving 
a lower end 40 of the handle 26. The end 40 is formed with a reduced 
diameter so that it is relatively flexible as compared to the remainder of 
the handle. The extreme lower end of end portion 40 may be slightly 
enlarged and the aperture 38 formed with an undercut opening allowing the 
end portion 40 to snap into aperture 38. In another embodiment, the lower 
end 40 may be threaded along with aperture 38 for removably connecting 
handle 26 to pad 36. In the particular embodiment shown in FIG. 3, the 
extreme lower end of end portion 40 terminates in a truncated pyramid 
shaped member 42. A mating dovetail slot 44 is formed in pad 36 so that 
member 42 can be slipped into slot 44 from one side of pad 36. The slot 44 
extends into pad 36 a distance sufficient to center handle 26 over pad 36 
when member 26 is fully inserted. 
FIG. 4 is an exploded view of the joystick 10 as shown in FIG. 3, i.e., the 
multi-arm member 14 and pad 36 are in cross-section. FIG. 4 illustrates 
more clearly the configuration of end member 42. This view also 
illustrates end portion 40 as including a reduced diameter portion 46 
which allows flexing of the handle 26 about pad 36. 
In using the inventive joystick, varying degrees of sensitivity, i.e., the 
amount of movement of handle 26 necessary to depress a key, can be 
achieved by adjusting the position of multi-arm member 14 on handle 26 so 
as to vary the distance between arm ends 18 and their associated keys. 
While the principles of the invention have now been made clear in an 
illustrative embodiment, it will become apparent to those skilled in the 
art that many modifications of the structures, arrangements and components 
presented in the above illustrations may be made in the practice of the 
invention in order to develop alternate embodiments suitable to specific 
operating requirements without departing from the scope and principles of 
the invention as set forth in the claims which follow. Furthermore, while 
the invention has been disclosed in conjunction with a computer keyboard, 
it will be apparent that it is useful in operating other types of keypads.