Power control latch

A power control latch which is connected to an electronic device having first and second parts which are movable relative to each other between a first position and a second position. The power control latch includes first and second electrically conductive members and a nonconductive member. The first and second electrically conductive members are connected to the first part of the electronic device and the nonconductive member is connected to, and extends outwardly from, the second part. When the first and second parts of the electronic device are in the first position, the first and second electrically conductive members are electrically connected to conduct power. When the first and second parts of the electronic device are in the second position, the nonconductive member extends between the first and second conductive members and prevents electrical connection therebetween.

FIELD OF THE INVENTION 
The present invention relates generally to power control devices and, more 
particularly, to a power control latch for use in a split keyboard which 
conducts power when the keyboard is in a first position and prevents 
conduction of power when the keyboard is in a second position. 
BACKGROUND OF THE INVENTION 
Split keyboards for computer terminals, in which a conventional keyboard is 
divided into a plurality of cooperating sections with keys, are known and 
are desirable for many reasons. The cooperating sections of the keyboard 
can be folded relative to each other to occupy a small space for storage, 
such as with a laptop or palmtop computer, and can be relatively 
positioned to provide comfort to a user during operation of the keyboard. 
U.S. Pat. No. 5,424,728 to Goldstein and U.S. Patent Application No. (Not 
Yet Assigned) to Kurokawa et al., Attorney Docket No. 8194-116 and filed 
Sep. 15, 1997, both disclose split keyboards having mutually detachable or 
pivotable keyboard sections. 
Conventional keyboards can include a power control key which toggles On/Off 
the flow of power in the keyboard to electrical circuitry, such as to 
circuits for wireless communication with a computer, or to an attached 
computer. Accidental actuation of the power key is particularly 
troublesome for wireless split keyboards which tend to be moved about 
while stored and where a battery provides a limited power supply life for 
keyboard circuitry, such as for wireless communication circuitry. Power 
control keys have been recessed in the keyboard to minimize any accidental 
actuation of power. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a power 
control latch which prevents accidental actuation of power. 
It is another object of the present invention for the power control latch 
to conduct power when the parts of the device to which it is connected are 
in a first relative position and to prevent conduction of power when the 
parts are in a second relative position. 
It is yet another object of the present invention for the power control 
latch, when connected to a split keyboard having movable keyboard 
elements, to conduct power when the keyboard is open and to prevent 
conduction of power when the keyboard is closed. 
It is a further object of the present invention for the power control latch 
to retain the parts of the device or keyboard in a closed position. 
These and other objects are addressed by a power control latch which can be 
used with an electronic device which has first and second parts that can 
be moved relative to each other between first and second positions. The 
power control latch includes first and second conductive members and a 
nonconductive member. 
The first and second conductive members are connected to the first part of 
the device in close proximity to each other. The second conductive member 
is resiliently biased toward the first conductive member such that a 
portion of the first and second conductive members are electrically 
connected when the first and second parts of the device are in the first 
position. The nonconductive member is connected to and extends 
sufficiently outwardly from the second part to extend between the first 
and second conductive members and prevent electrical connection 
therebetween when the parts are in the second position. 
In another aspect of the present invention, the power control latch is 
connected to a keyboard that includes first and second keyboard elements 
connected to a rotatable coupler which allows the first and second 
keyboard elements to be pivoted between an open position and a closed 
position. The first and second conductive members are connected to the 
first keyboard element and the nonconductive member extends outwardly from 
the second keyboard element. In the open position of the keyboard 
elements, the second conductive member is resiliently biased toward the 
first conductive member so that a portion of the first and second 
conductive members are electrically connected. In the closed position of 
the keyboard elements, the nonconductive member extends between the first 
and second conductive members to prevent electrical connection 
therebetween. 
In this manner, the flow of power through the power control latch is 
actuated by the relative position of the parts of the device or keyboard. 
For a split keyboard, the power control latch conducts power when the 
keyboard is open and prevents power conduction when the keyboard is 
closed. Accidental power actuation is avoided while the keyboard is 
closed, such as when the keyboard is stored in a briefcase. Moreover, 
power conduction is automatically halted when the keyboard is closed and 
is initiated when the keyboard is opened. 
In further embodiments, the power control latch is adapted to resist 
separation of the keyboard elements when the keyboard is closed, thereby 
facilitating storage of the keyboard.

DETAILED DESCRIPTION OF THE INVENTION 
A wireless split keyboard 10 in a fully-closed position is shown in FIG. 1. 
The dimensions of the keyboard 10 can be suitably selected to allow the 
keyboard 10 to be stored within a relatively small area, such as with a 
portable laptop computer, palmtop computer, or cellular terminal. The 
keyboard includes left and right keyboard element 12 and 14, respectively. 
A pivotal coupler 16 connects the left and right keyboard elements 12 and 
14 and enables the elements 12 and 14 to be angularly displaced relative 
to each other. The keyboard 10 is shown in a fully open position in FIG. 2 
and is shown in FIG. 3 in a partially open position with keys and upper 
cover removed. 
Referring to FIG. 3, the keyboard 10 includes electrical components 20, 
such as a keyboard decoder and infra-red communication circuitry which 
transmits any key actuations to a remotely located computer, a battery-22, 
and a power control latch 18. The power control latch 18 controls the flow 
of power from the battery 22 to the electrical components 20 and secures 
the keyboard elements 12 and 14 together during storage (i.e. closed 
position in FIG. 1). The keyboard 10 can include further electrical 
components which are powered independently of the power control latch 18, 
such as for components which are to be continuously powered or selectively 
powered by another power switch. 
Referring to FIG. 4 which shows a sectional view of the keyboard 10 in FIG. 
3, the power control latch 18 includes a latch member 24 which extends 
outwardly from keyboard element 14 and a latch spring 30 which is 
connected to keyboard element 12. The latch spring 30 includes opposing 
leaf springs 32 and 34 which releasably mate with the latch member 24. 
The leaf springs 32 and 34 are formed from a resilient conductive material 
(e.g., metal). Leaf spring 34 is connected to the battery 22 to receive 
power therefrom while leaf spring 32 is electrically connected to the 
electrical components 20 to conduct power thereto. The leaf springs 32 and 
34 are resiliently biased to contact each other and, thereby, form a 
closed circuit between the battery 22 and electrical components 20 when 
the keyboard elements 12 and 14 are angularly displaced a predetermined 
angle. The 
The latch member 24 is formed from a nonconductive material (e.g., plastic) 
which, when inserted between the leaf springs 32 and 34, prevents the flow 
of power from the battery 22 to the electrical components 20. The leaf 
springs 32 and 34 provide a clamping force on an enlarged end of the latch 
member 24 to resist separation of the latch member 24 from the latch 
spring 30. 
In this manner, when the keyboard elements 12 and 14 abut in a closed 
configuration for storage, as shown in FIG. 1, the latch member 24 mates 
with the latch spring 30 to prevent the flow of power from the battery 22 
to the electrical components 20 and to retain the keyboard elements 12 and 
14 in the closed configuration. In contrast, when the keyboard elements 12 
and 14 are angularly displaced from each other, the latch member 24 is 
withdrawn from the latch spring 30 and power flows from the battery 22 to 
the electrical components 20. 
Another embodiment of a power control latch 40 is shown in FIG. 5. The 
power control latch 40 includes a conductive leaf spring 42 and conductive 
contact pad 44, both of which are connected to the keyboard element 14, 
and a nonconductive latch member 46 which extends outwardly from the 
keyboard element 12. The leaf spring 42 and the contact pad 44 are 
connected to the electrical components 20 and battery 22, respectively. 
With the keyboard elements 12 and 14 angularly displaced relative to each 
other (i.e. open configuration as shown in FIG. 5), the spring 42 contacts 
the pad 44 enabling power to flow from the battery 22 to the electrical 
components 20. In contrast, with keyboard elements 12 and 14 abutted (i.e. 
closed configuration as shown in FIG. 1) the latch member 46 electrically 
isolates the leaf spring 42 from the contact pad 41 and prevents power 
from flowing between the battery 22 and the electrical components 20. A 
recessed channel 48 is defined in the latch member 46 to engage the leaf 
spring and resist separation of the keyboard elements 12 and 14 when the 
keyboard 10 is closed. 
As can be appreciated from the preceding discussion, the power control 
latch conducts power when the keyboard is open and prevents power 
conduction when the keyboard is closed, thereby avoiding any accidental 
power actuation while the keyboard is closed, such as when the keyboard is 
stored in a briefcase. Moreover, power conduction is automatically halted 
when the keyboard is closed and is automatically initiated when the 
keyboard is opened. Additionally, the power control latch resists 
separation of the keyboard elements when the keyboard is closed, thereby 
facilitating storage of the keyboard. 
While the invention has been described in connection with what is presently 
considered to be the preferred embodiment, it is to be understood that the 
invention is not to be limited to the disclosed embodiment, but to the 
contrary, is intended to cover various modifications and equivalent 
arrangements included within the spirit and scope of the appended claims. 
It would be appreciated by one who is skilled the art, after considering 
the present invention, that the power control latch can be used to actuate 
the flow of power through any electronic device having movable parts. For 
example, the power control device could enable/halt power flow in response 
to opening/closing a flip cover on a phone, laptop computer, alarm clock, 
or other electronic device.